Ok so from what i've seen some people are still struggling with some of the steps so i will write down the solution, the exact way that i got the Achievement..
Things you need:
- FOUR Players
- 31-79 JGb215 (Shrink Ray) THIS MUST BE PACK-A-PUNCHED FOR THE FINAL FEW STEPS. (It will become 'The Fractilizer')
- The Eclipse must be activated for EVERY step.
- The Eclipse is on a timer so be quick but careful for each step.
- If you have correctly completed a step the Eclipse will end.
Step 1: Turn on the power. I assume everyone knows how this is done.
Step 2: Activate the Eclipse. On the four walls surrounding Quick Revive are circular buttons with a skull on them. These must all be pressed to activate the eclipse.
Step 3: This step requires 2 players. One player (P1) must go through the spike trap on the Olympia side of spawn, go through the mud trap and over the bridge. The other player (P2) must go through the spike trap on the M14 side and go down to the bottom of the hill by the perk machine. A button with a skull will have appeared on the small structure next to the perk machine, where the two men can be heard, press the button. Twelve pads will appear on the floor.
Now one player must stand on a pad and see what the shape is, then step off the pad and tell your parnter on the other side what the shape is, they must then find the pad on their side that corresponds with yours. When the match has been found both stand on the pad and it will sink into the ground. Repeat for all of the pads.
Step 4: The two men are now drowning and you need to rescue them. To do this go through the tunnel at the bottom of the hill next to the perk machine, opposite the small structure (where P2 activated the pads in Step 3) and go all the way to where the water is spilling through. There is a Pressure Pad in this room, one of the grates above the water spillover compartment. Three players must lie/stand on the Pressure Pad. The other player must go to the top of the slide (Through the spike trap on Olympia side of Spawn, jump through the mud and to the left) the player must slide down and pull a lever by hitting X. The lever is on the right of the slide and about halfway down, you will see a small chute as a reference. A small click will signal youve done this right. You will then hear the two men telling you they're safe.
Step 5: A crystal ball will have appeared at the top of the slide from the previous step. Shoot it with the shrink ray, it will fall to the ground. You must then knife it into the slide and follow it down. when it reaches the bottom it will fly into the geyser, jump in with it and it will fly up onto a perch.
Step 6: The two men are now stuck in the catacombs and are choking on gas, go into the tunnel by the perk machine once again and find the pipe and connected valve (it is next to one of the PaP pressure pads) turn the red valve until the man tells you he can breathe. Now the gas should be leaking into the tunnel.. You must now get a Napalm Zombie to follow you from the tunnel entrance, all the way to the power room, ensuring the four gas leaks are on fire. When this has been done return to the valve and pull the lever to the right of it.
Step 7: Now you must assist the men in getting out of the catacombs. They are trapped by the big waterfall. You reach this by going through the mud trap and over the bridge, take the bottom path and go through the tunnel. Now, along the left side of the wall are 4 holes, place a spikemore directly in front of each hole and get a zombie/crawler to set them off, the hole should be plugged with the spikes. Make sure all 4 holes are plugged. Now run through the waterfall to the small pile of bricks in the middle of the water, there will be a protruding brick, and the message, 'Do Not Press X' obviously press it, it will fill the resevoir and aid the travellers escape.
EDIT: A napalm zombie can also be used to trip the Spikemores as he won't die from the damage. Thanks to 'exhaled again' for pointing this out.
Step 8: Once you activate the eclipse 12 panels will appear on the walls around the map. You must knife each panel (near the top of the panel itself) until they light up. The panels are located as follows, 5 in spawn (one on the walls of each of the spike traps, one opposite each of the spike traps, and one next to the big statue to the left of the giant staircase) 1 in the power room (to the left of the left power switch) 1 in the room with the Stakeout, elevator and all the water ( this room can be reached through the power room and also through the debris at the waterfall from Step 7.. the panel is on the left) The rest are on either side of the spike traps, on the Olympia side they are next to the pm63 ( straight over the mud trap ) and one over the bridge (by the PaP pressure pad) also there is one by the water slide entrance.
On the M14 side there is one on the wall directly past the spike trap, and one near the bottom of the hill (i think, not 100% on the last one but it is on that side.) Once all are glowing go to the minecart, (past the M14 spike trap and at the top of the hill) once there you will see a snare trap on the grass outside the map, throw an explosive at it to destroy it.
Step 9: There are 4 circular dials in the mud trap room. These must be swiveled so that they display the numbers 1, 3, 4 , 16. The numbers are in Mayan and correspond as follows..
A dot = 1
A line = 5
A rotated C = 10
You are looking for the dials with, one dot, three dots, four dots and one with a slanted C under a line and a dot. Roate until these are at the top.
Step 10: Now you need to get the dynamite and shrink the meteor. Firstly you need to hit the gongs that make a low sound, there are 4 you need to hit. There are 8 gongs on the map and the 4 required are random. Once all four are hit the orbs will begin to glow. The dynamite is regularly on the orb atop the structure past the M14 side spiketrap, to dislodge it you must shoot one of the orbs with the Pack-A-Punched Shrink Ray, the ray will ping off the orb and dislodge the dynamite, stand underneath it and catch it.
Now, to shrink the meteor shoot the orb that is furthest on the right (the room on the olympia side, above the mud trap) the ray will then ping between all the orbs and finally shoot towards the meteor shrinking it. (NOTE: If the Eclipse ends which it did for me, re-activate it and shoot the orb again.) Once the meteor is shrunk you must get up the steps. To do this you must stand on the four PaP pressure pads around the map, these are in spawn, by the bridge, in the tunnel, and by the power. A spinning statue will signal that you're near. Once all have been activated return to spawn and run up the steps. You will hear some dialogue and eventually the dynamite will be removed from your 'inventory' they tell you to stand back while they blast the wall open. (Normally the water pushes you back down, simply re-activate the steps and return to the top, also the eclipse may have ended and you cant reset it. that is Normal) Go all the way to the top and the newly opened wall and you will see an altar with an interesting inscription at the bottom, and a floating rock on top. Grab the rock and the achievement is yours.
Final Notes: The person who grabs the rock will get all 7 perks PERMANENTLY, even if you down and bleed out they remain with you.
Also this Easter Egg can be repeated!! When it is complete a radio will appear at the bottom of the giant staircase, listen to the dialogue and you can then start the Easter Egg all over again, meaning someone else (and eventually all players) can get permanent perks.
This solution is the EXACT way i got this Achievement with 3 friends. If you have any questions just ask me, and if you leave a negative vote please say why so i can amend the solution.
Many Thanks, Hope This Helped