I got new rollers from Ames Performance. Part number J134M, 3 pcs set for $14. These included the metal stud. Easy to install. Drill out or grind away the old rivet stud. Inset new ones and peen over the metal stud. Make sure that the metal stud is peened over tightly against the 1/4 window frame. Clean out the old grease from the track and use lithium grease. If your electric windows operate slowly or if you manual window are difficult to crank, most likely, it's the window regulator rollers that are broken or stuck.
John