(adsbygoogle = window.adsbygoogle || []).push({});
Location: The room with the Thompson, grenades, and double-barrel.
Okay so go to where the Mystery Box is in that room (it doesn't have to on or active or whatever) and notice to the left on the wall. There is scrap metal as some sort of barrier-like thing. Go on the left side and you can jump on a ledge. This might lead to getting out of the map because there is a small window above you could maybe crouch though. Or you can try a 2 person glitch or something crazy like that...
Just saying.... and don't say anything like "I'll believe it when I see a video" cause that pisses people off
Remember it's a LEDGE, not a corner where you have to hold forward to stay up.