Dead Rising: Zombie Genocider
First of all, head to Paradise Plaza and go up the stairs and locate Columbian Roastmasters.
Stock up on orange juice. If you run into large groups of zombies find gaps and jump alot.
Go back down the stairs and near them are restrooms where you can save and a locked door.
Next go across from the restrooms head outside of the mall to Leisure Park.
Locate the Maintenance Tunnels and then use the red car to go into the tunnels.
From the loading screen, go right, left, then right again to get to the location of the key.
The key will unlock doors back to the surface so you can save again,etc.
Jump to avoid zombies as you backtrack out of the tunnels back to the red car.
Once back to the red car go back down the tunnels and refer to the vehicle paths to take.
At the white car there is a door where you can go in. Head left for an elevator for safety.
Once youre on the upper level you can go through the now unlocked door to restrooms.
Feel free to get more orange juice or anything else you may think is useful upstairs if needed.
Remember to save often and be prepared for vehicle breakdowns or stalls.
But most of all, REMEMBER TO COMPLETE ALL 3 DAYS! Meaning get some sort of ending.
If done correctly you will get a confirmation of Real Mega Buster in the security room.
This is for all future playthroughs btw and although it only has 300 rounds it respawns.
Below are visuals that can better help you. Good Luck!
Location of Maintenance Tunnels/Map for rest of locations:
Location of Maintenance Tunnels Key:http://dead-rising.wikia.com/wiki/Maintenance_Tunnel_Key
Maintenance Tunnel Vehicle Paths:http://faqs.ign.com/articles/726/726004p1.html
Sources: tty.wanfear.com, dead-rising.wikia.com, faqs.ign.com