use the flux rifle to snipe all the robots at the base. Then activate 1 of the big turets by walking to the side of it. Then keep doing side flips over the bullets and fire the flux when you hit the ground. once you destroy the turrets go inside . if opponate has put mines every where then use the lave gun because it still fires once you die.
Turn on first person mode then jump twice,hit box. If your wrench hits a wall or invisible barrier, keep tappin box. You will be climbing the wall
NOTE:You have to be in the air when the wrench hits the wall!