This is my first time ever attempting to replace these. There is a black plastic disc and a strange looking lock washer. Anyone know the proper method to remove the old and install the new disc/washer? The old disc just spins when I turn it, while the washer is fixed in place on the seat track stud. Same thing happens with the new one. Disc will spin while washer doesn’t rotate.. In the past it looks like someone had siliconed the old washer to the old disc so they would rotate together, as one unit. The new ones and unsiliconed old ones don’t rotate around the stud together.