I am going to use the KWA M11a1 Diagram, hope that's ok?
Step 1: Remove the Charging Handle by Twisting the knob and Pulling Up. A small like ball bearing holds it in place.
Step 2: When bolt slides out remove parts# 28, 29, & 40 to take out the piston.
Step 3: If you can; slide out the loading nozzle cover without removing the spring it's attached to. You can remove the spring but it can be a pain to place that spring back on.
Moving On; This is where I am currently stuck.
Step 4: Remove the pin, part# 48, that holds the insides of the piston together.
Step 5: The inside parts should slide out the rear. Currently i am having difficulty trying to remove part# 46. Seems to be really stuck.
Step 6: Replace the inner piston, part# 43. Just put it on the spring.
Step 7: Put it all back together.
That's it! Takes about 30 minutes to do unless your part# 46 gets stuck like mine.
Quick Update: I just got part# 46 out by using two pliers. I placed the rear screw back into this part and used that as a part to grab onto. Took awhile and some muscle strength but I did get it out!
Edited by Villain, 18 November 2008 - 09:48 AM.