The regulator assembly has all new rollers already in it - no need to get others if you are replacing the regulator.

If you plan to replace your lock actuator, I'd really suggest waiting and do both at the same time - to replace the lock actuator, you need to remove everything just like you are doing the regulator (PLUS the regulator, PLUS the window frame). If you do the regulator and door lock at separate times, you end up just doing most of the work twice (assuming it's the same door with both problems).

Take your time - it took me about 2 hours to do the first regulator. Now I can replace one in about 30 minutes :-)