My rear window will not go up or down using the.

If your regulator is still in good shape it is likely the window motor plastic gears. You can either buy a cheap gear kit, they are sold on several sites and some auto parts stores carry them or simply replace the motor. If the cable/regulator assembly is still in good shape( the part the motor is screwed into). The trick is to seperate the regulator assembly carefully from the motor otherwise the cable will come loose causing you to have to buy a regulator assembly and more work installing. Hold the spool in place as you slowly pry the motor off the assembly. Once removed you need to keep the spool in place.A few plastic ties etc. If you are going to attempt to work on the motor( one screw generally holds cover to motor).