Here's a DIY article on replacing a GM window regulator--with photos

Replace window regulator

 

Manufacturers have redesigned power window mechanisms and you’re paying the price for it. The new mechanisms, known as window regulators, are lightweight and flimsy. They raise and lower the window with cables that often bind or break. If the window channels aren’t lubricated (use silicone or dry
Teflon spray), the friction overloads the motors and they burn out or strip the “spool” that winds the cables.

Rather than pay a shop $350 to replace the regulator, do it yourself. Start by buying a subscription to Mitchell online (http://www.eautorepair.net) or Alldata (http://www.alldatadiy.com/) and print out the diagrams of the door trim panel fasteners. Knowing where the hidden fasteners are will save a LOT of wasted time and frustration. (Be a sport and buy a subscription—after all, you’re saving several hundred dollars by doing it yourself).

Next, go to www.dormanproducts.com and look up the number of the replacement regulator for your vehicle. Dorman specializes in fixing the manufacturer’s defective designs and offers a new part for a lot less than the dealer. Then call your local auto parts store and see if they stock the Dorman part. If not, try www.rockauto.com. There are a few other companies making aftermarket window regulators. I have no experience with those other companies, so I can’t vouch for their quality.

The only special tool you’ll need is a trim panel remover tool (about $5 at any auto parts store). Start by removing the visible screws. Then pop off any plastic “vanity” caps that appear to serve no useful purpose. You’ll find they’re covering screws. Almost every car I’ve ever worked on has screws or bolts holding the arm rest to a bracket. Once again, look for
plastic “vanity” covers if you
can’t find those fasteners.
(See the photo)

Once the screws are out, start at the lower portion of the trim panel and begin popping out the plastic “Christmas tree” fasteners. They’re usually located along the perimeter of the door. (See photo)

Lift the trim panel up and off the door.
Then disconnect the electrical connectors
to the window and door lock switches. (See photo) With the trim panel now removed, peel off the vapor barrier. (It has to go back on, so be careful while removing it)

Take a look at the photo of the window regulator I shot from the outside (Yes, I DID cut a hole in a door just so you
can see what you’re dealing with.
It was a junkyard door so don’t freak out on me. That’s also why it’s so dirty. If you want me to shoot pictures of clean doors, simply mail me a check for $145 and I’ll spray some Windex on it next time. In the meantime, you’re getting this for free, so quit complaining)

You can see that the regulator is really a very simple mechanism. The window sill gets pulled up and down by the cable. Your next step is to remove the window glass. To do that, you’ll need to move the sill down so you can reach it with your sockets. Remember, you’re doing this from the inside (unless you too want to cut a hole in your door). Can’t get the window into position so you can remove the glass? Reach around the regulator track from the inside and cut one of the cables with a wire cutter. BUT MAKE SURE you’ve got someone holding the glass! Then lower the glass, remove the bolts and pull the glass up and out. The glass pulls out by tilting it towards the outside of the door.

Next, disconnect the electrical connector from the motor. Then you can remove the fasteners holding the regulator in place. Tip the regulator and feed it out through a hole in the door panel. If you can’t get it out and you haven’t already snipped a cable, do that now. That will allow you to move the sill up or down.

Here’s a tip: The inside of your door contains sharp metal edges. WEAR LEATHER GLOVES!

All these instructions are for cable regulators. If you have an older vehicle with a scissors style regulator, you can fix those too. BUT heed this warning. Scissors style regulators usually have a coiled assist spring—like a clockspring. You must secure this spring before you remove the motor. Skip this step and your next move may be to the ER for a broken finger! The easiest way to secure the spring is to drill a hold in the regulator and insert a nut and bolt through the spring to clamp it down.

Dorman sells replacement motors. But if you have a cable regulator, you may find that the old motor is riveted in place. If you want to spend the time to drill out those rivets, be my guest. But once you remove the motor, you may find a stripped cable spool. That’s why I recommend replacing the entire regulator. That, plus the fact that Dorman has fixed the problems that plague the OEM models.

Reverse the entire procedure to reinstall.

Not sure if the problem is in the regulator? Here’s how to check. Window motors only have two wires going to them. The window switch alternates the power and ground connections to power the motor up and down. So, attach the positive and negative probes of your digital volt meter to the electrical connector going to the motor. Then flip the window switch in both directions. You should see the voltage change from +12 volts to -12 volts. If you see that, it means the motor is getting power from the switches. Switches good. Motor bad.

 

has any one done this how hard is it did you buy parts from sites listed here & how are they workin for you