This glitch may give you a CLIENT ERROR. Only post replies about the glitch.
To start off,
1. You will need 2 players. [PLAYER A, PLAYER B]
2. Both players meet on the box. This box is the box that is located above the staircase.
3. One player will take out a PISTOL while the other holds their knife.
4. Once the play shoots the wall, both players jump on the bullet hole.
5. Once you've done that, you should have gotten up on the roof.
[EXTRA]6. There is another glitch, while on the roof, run across to the BL side.
[EXTRA]7. On the BL Side, jump on the blackboard.
[EXTRA]8. Kill the from their base without them knowing.