Hi! I have a 1990 Suburban. The driver side power window stopped working and I'm going to replace the motor. I had a few questions: 1. Do I have to remove the regulator? Or can I just remove the motor? 2. The autozone site says I need to drill a hole in the regulator and use a screw to keep the arms under tension? I replaced a lot of motors/regulators but never had to do this. Off topic...I also wanted to change my front diff fluid. Do you know what viscosity I need? Do I need to remove the cover or can I just suck it out the fill hole? And then do I fill it till it comes out the fill hole? Or do I put in a certain amount. thanks!