Setup for level 1-4
Starting location - undercover in garage
Concealed weapon - I used the HWK 21 covert for its 20 round magazine
Gear - whatever explosive items you have. I used "remote explosive duck" and "The iconater"
Agency pickup - hay shed - You can put something here or not. I put the exploding phone there just in case I didn't get him with the explosives i brought with me.
Level 1 - Kill Mark Hicks in a hay baler or an explosion.
Level 2 - Kill Preston Becker in a fire or crushing him under a car. Kill Mark Hicks in a hay baler or and explosion.
Level 3 - Same as level 2 but now someone is hunting you. The hunter is the elite soldier i shoot through the window in the door at the beginning of level 3.
Level 4 - Same as level 3 but you can't kill the hunter.
Setup for level 5
Starting location - undercover in garage
Concealed weapon - HWK 21 covert
Gear - change one slot to lockpick and keep the other as an explosive
Agency Pickup - change to south perimeter and put a tac smg in it
Level 5 - Kill Mark Hicks with the Old Axe and kill Preston Becker with an smg while disguised as the scarecrow. Still being hunted by hunter, still can't kill him.
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The new Colorado escalation The Farley Crescendo makes this achievement way easier.
Stage 1 and 2 can be completed by starting in the house disguised as a hacker and just going downstairs and shooting both targets. The bridge exit is nearby and is a quick way to escape.
Stage 3 is slightly more complicated because now you have to hack a computer. The computer is right next to the room you start in as a hacker. Kill both hackers in the room and use the computer. Around the time you finish with the computer the guard on the balcony will come inside and notice a body. Quickly take the soda can and knock him out by throwing it at him. Then just go downstairs, shoot the targets and run to the bridge.
Stage 4 can be completed the same way as stage 3.
Stage 5 only changes the location of the laptop. When stage 5 starts wait for the elite guard to go onto the balcony and run to Rose's room and pick the door. Shoot the guard in the room and use the laptop. Then just go downstairs, shoot both targets and run to the bridge.
I got spotted killing the targets all 5 stages and managed to run to the bridge taking minimal damage, so stealth isn't too important.