Thing Boss 2

Open the door on your right.  Next fix the winch.  Now move to the crates and throw grenades at The Thing.  When you are ready, switch to the flame grenade launcher. 

Run out from behind the crates and hit the thing being careful to keep moving.  Once the thing is stunned, hit it between its two arms.  If it is still alive, return to the crates and repeat.

Once you win, go to the wall switch beyond the thing and hit it.  Repair the power panel.  Run all the way to the elevator you took to enter this area and the level will end.