Hi All, I recently bought a 1984 190D and want to replace the rear brake discs. I have already replaced the pads and I originally wanted to do both at the same time, but since I already had the wheel off I felt like I had to do something while I was there.

The problem I'm having is the Haynes manual I have (for just the generic 190) and the brake discs I actually purchased online are different than the ones which are actually on the car.

The difference is that the discs I bought (and the ones pictured in the manual) have the disc locking screw, whereas the discs on the car have no locking screw!

So I'm wondering:
1. How do I go about getting the existing discs off in order to put on new ones?
2. How terrible would it be for me to use the discs I bought on the car, even if the locking screw is not used and the hole for it sits empty?

Thanks in advance!
Louis