Originally Posted by glennhl

Actually, if you get the correct pinion puller, it pulls the gear off by pushing on the motor shaft. It does not put any load on the motor bearings.

Originally Posted by rcbuggy88

If you pull it and the setscrew is stuck on, then you will put unnecessary lateral pressure on the front motor bearing (which may not matter but just know that that is the opposing force). I would just use a Dremel and be careful not to go too deep and hit the rotor. A pinion is a relatively cheap thing to replace. There are no other options that I've heard of.