I have an 82 GSL Rx7 and I am having problems with my windows slipping off of the track. I fixed it before but recently it fell off again but I cant seem to figure out how to get the plastic plugs off that cover the holes for the screws. Well, without destroying all of the surrounding plastic with a flathead screwdriver... Any tips?

 

a screwdriver with a small tip like ones used for taking apart electronics works better, wrap electrical or duck tape around it.