how do you open the "back doors" on the level standoff in halo 3?

[cam_daddy09 b]

id like a detailed description of how to open them.

 

[Dylan K]

near the back side edge (say, oh, front is south, so itd be like northwest) There is a gray box on the exterior wall. you can flip the switch to open a fourth lower entrance and to open some windows that are very protected.