I just went for it and figured it out as i went. Took pictures every 30 seconds to make sure i remember how to put it back together.
I also found a site that describes it step by step afterwards and will be a great help when trying to put it all back together. Here it is:
http://unconventional-airsoft.com/20...on-and-review/
If there is something wrong in the hammer assembly it is (most likely) either the impact hammer, or the sear (part which holds the hammer in place after cocking it). Before installing ANY of the replacement parts keep your eye out for any defomities. They are often have sharp edges from either casting or CNC'ing, so use a very fine file to smooth it out.