A step by step guide in rebuilding those factory power window motors.

After removing the motor remove the top cover.
You can see in the second photo all the small broken bush parts.

 Remove the top gear and then lift out the plastic white gear with a pair of point nose pliers.

Give it a good clean out and replace the complete gear.  Available in the shop section.

Pack with plenty of grease and now it's ready to re assemble.