Replacing these just takes time. The rear door panel needs to be removed. Then you should notice a large scissor like mechanism, it is very important that these be locked together during the service procedure as they are under a lot of spring tension and are capable of severly injuring you if you do not take the time to immobilise them before removing the motor. Take a drill and drill a hole through the arms near where they intersect and pivot so that you can insert a bolt and nut to keep them from rotating when you remove the motor. Otherwise they are cabable of removing fingers. Once you have then take the motor off of the regulator and install the new one. Then remove the bolt and nut you installed , reassemble and test.