My 00 GTI GLS hit 30,000 miles this week. I finally got around to changing transmission fluid. Should have done it sooner. It is not difficult. Here is how I did it:
Redline MT-90 or similar, 3 quarts
StaLube fluid pump, about $6 from Pep Boys, etc.
17mm allen wrench or socket
Torx driver to remove lower engine aero cladding
Teflon tape (optional)
I drove the front of my car up onto ramps. Then I jacked up the rear of the car and put jackstands under it. This makes the car approximately level. Remove lower engine aero cladding (4 torx screws) as you would for an oil change. Remove the fill plug first. There is no sense in draining the oil unless you can get the fill plug off the car. The plugs are remarkably similar to the ones BMW uses.
Mine were not torqued very much. If I had to guess, I would say less than 50Nm.
After the fill plug is removed, clean it and set it aside. Now remove the drain plug and catch the fluid. My fluid came out pretty dark gray. Clean the drain plug. I wrapped each of my plugs with 2 wrappings of teflon tape. This is probably totally unnecessary, but I did it anyway. My drain plug appeared to be leaking a little fluid (see black areas in pic above) so it was either undertorqued or something is not machined correctly. Replace drain plug. Torque to 50Nm = about 39 ft-lbs. or whatever you like.
Use the StaLube pump to pump the new fluid in.
I pumped directly from each of the redline bottles. It's messy but cheaper and easier than buying an empty bottle to pump from. Capacity is about 2.1L right on the nose. Once fluid starts to run out of the fill port, stop and replace the fill plug. Again 50 Nm or thereabouts. Clean and degrease all surfaces. I went for a 10 minute test drive and then checked for leaks before replacing the aero cowling. I'll check for leaks one more time in about a week.
My car shifted really well before Redline, and it still does now. I don't feel any difference other than piece of mind that the fluid is new.
00 GTI GLS 1.8T Cosmic/Beige
01 M Coupe Imola/Walnut/Extended