In the level "Bio Labs Holding" there is a room which has a door that won't open and walls that won't break. You enter the level, go into the room with the extraction point, and it's in the far, upper left corner of this room. Use Noghtcrawler to teleport into the room , stand on the two giant metal tanks, and teleport towards the back of the room. Nightcrawler will go past the wall and be almost at the very end of the level.
WARNING!!!!!!! there are 6 sentinel advanced where you appear, so have fun