Working on one of my 66 Satellite's quarter windows with a roller replacement kit. After much pain, cuts, blood, etc., I have the window back in with all the rollers in the right places. I can't for the life of me get the little black steel retainers locked onto the back sides of the roller shafts. Two hours (maybe three) and I've now lost one inside the quarter panel. Is there a trick to getting these stupid things on? How do you pros do it?