[cratedriver]

I agree. Not that hard at all. Just take your time and be patient.

http://www.airsoftplayers.com/mechbox/tutorial.asp

http://www.airsoftplayers.com/ftk/tutorial.asp

http://www.airsoftplayers.com/manuals.asp

I just got my Systema gears installed last night with new bushings and shims. She works awesome now. Read the info in the above links and things should go well. Just be careful with setting the gears and shims properly.