nathan.never
Super Freak
Good job, but I am not lucky enough to have your skill level to fix them!
Actually it is not hard at all. First you have to remove the forearm armor - just unstrap two leather braces and remove the armor. It is easier to rotate the forearm without the armor and you also don't risk breaking the armor straps.
Then you pull out the deformed fist and pull the red shirt up until you see the bare forearm. You hold the arm above the elbow (between the elbow and the lump) and with your other arm slowly twist the exposed end of the arm until you get it right.
Hope this helps.
See - it looks much better now: