There is no need to remove the rear glass when removing the regulators but use tape on either side of the window, run over the top of the door as a little security.

The regulator is held in place by rivets- two at the top, three holding the backet with the motor and one stablising the bottom of the regulator. Use your drill, holding it as straight as possible so the holes in the sheet metal aren't enlarged and simply drill until the visible disc of the rivet spins up the bit.

One you have removed all six rivets, the only thing holding the regulator in place is the slide and bracket on the glass. A bit of WD40 will make it a little easier to slide the white plastic guide out of the bracket and then it's simply a matter of removing the assembly through the large inspection cut out.

The factory VN, VP and VQ units will be a solid guide, riveted to a bracket which holds the motor and lower pulley assembly stamped with BROSE. Aftermarket units and VR - VS types do not have a bracket for the motor but instead float and are only held in place by the door sheet metal once riveted in place. Having said that, the items are interchangable.

By this stage, the regulator has been in service for some time and will probably be looking a little worse for wear. On mine there was a fair amount of crap built up in the runner iteself which was simply cleaned with a rag.

Part Four - Checking The Cable

You will notice that a cable runs from the top and bottom of the slide, through pulleys- one at the top and one at the bottom- and into black plastic regulator and should been reasonably tensioned. Excessive tightness or massive amounts of slack indicate there is a problem with the cable itself.

If you suspect the cable is the problem, the top cover can be removed using your torx driver. Simply undo the screws and prise the lid off. Beneath you will find a large plastic reel with the cable wrapped around. Be aware that if you choose to remove the reel, the cable will most likely jump off and need to be rewound- if you don't need to do it you are just creating work for yourself!

If the cable need to be rewound, simply place the cable ends in the recess (bottom cable starts at the top of the reel, top cable at the bottom) and is tightly wound. It can be frustrating winding one while keeping tension on the other but I struggle rewiring a whipper snipper so you might have more luck than me!

On one side of my windows this cable had jumped off the reel and caused a tangle so it was necessary to remove the reel and rewind it. The underside of the reel has three recesses where black plastic rubbers are placed to give it a more positive fitment against the drive cog in the base. If you lose these, the assembly can be reassembled however it won't be quite as responsive as the drive cog will have to move and take up the slack before the reel is driven to wind the cable.

One thing I noticed with this problem was the cable itself had actually stretched and each time it was driven by the motor it would simply jump off the reel and another tangle would result. I had no luck finding a replacement cable and the VN / VP slide and cable seems to be a complete unit so the regulator itself had to be replaced.

Part Five - Checking The Motor

If your cable is fine and there is no obstruction on the guide runner itself (and of course you already checked for power at the plug!) the last piece of the puzzle is the motor itself.

The motor is held to the regulator by two torx headed screws which when unscrewed will allow the motor to slide away from the rest of the assembly. The drive shaft is spiralled to mesh with a cog and drive the cable reel so you may need to manouver the motor a little to get it free- brute strength will probably damage the plastic cog.

Coming loose with the motor will be a black rubber gasket to seal it against outside elements.

With my unit, whatever lubricant used previously had soldified and was restricting the motor spinning in the housing. All that was required was a good clean, a light sand to remove some corrosion and a relube with nickel grease. Again the jumper leads came out and the motor spun up while away from the rest of the regulator to confirm the motor was driving.

With the motor confirmed as serviceable, I removed the top cover of the cable reel to clean out any left over gunk and then put the regulator and motor back together before testing it as a whole assembly with the jumper leads.

Part Six - Reinstallation

Once you are happy you have a working window regulator assembly it can be riveted back into your door. I stress the importance of testing the regulator before re installing it- however make sure the guide is correctly positioned to slide it back into the window bracket.

Place the regulator in so the top of the regulator is towards the front of the car as I found it easier to slide the guide into the bracket from the front of the car, pulling rearward. Some lube might be needed to help it into place.

Once the guide and bracket have been reunited it is simply a matter of re-riveting the brackets in place (two at the top, four at the bottom) ensuring all cable as clear and aren't going to get sandwiched between the regulator and door.

Once you have replugged the motor in it is probably a good idea to test it from your switch block before you attach the sealing panel and door trim itself.

If everything is working as it should, you can reinstall the door trim and be satisfied any passengers in the back will have working power windows!