all you do is seperate the grip frame from the solenoid housing and pop the two clamps off of the pins and slide the stock trigger out, then place the wermstick in and put the pins back in, clamp them back on and put grip frame back on solenoid housing. As for the new frames mine is #5541 and has a new style frame.
Impulse #5541 with gadget grip, wermstick, and white delrin bolt
First off, if you read my last post here, Im sorry, I screwed up. I did install the blade, and there is NO resistance on it.... Don't give up on this triger when you get it on, gas up your gun and see what you can do with it. It took me about a hour and a half to get it to where I was happy, but sure enough, its AMAZING!! I can chop paint twice as fast now!!!!!