Did an oil change on my TDI today (5,200 miles on it). Also took some pictures along the way so I thought I would share them here.
Starting with materials needed: 9 liters of Castro Motor oil, a new oil filter. Tools needed: T30, T24 torx bits, 32mm socket.
Steps I took:
1. put touareg on a set of ramps.
2. remove the underbody panel: There are 11 T30 tourx screws holding the two-section panel in place. 2 holding the front section to the body, 3 holding the front section and the lower front bumper together, 4 holding the front and rear sections together and to the body(shown in the middle of the picture), 4 holding the rear section in place(shown in the bottom of picture). There are also 4 T24 torx screws holding the front section to the fender wells. After they all come off, the panel comes off. The drain plug is easily seen at this point.
3. remove the drain plug (6mm allen key)
4. remove engine cover, remove the filter cap with a 32mm socket. The filter element pulls out with the cap.
5. remove the filter from the cap and replace the o-ring with the new one that comes with the filter.
6. install the filter into the housing first before putting the plastic cap back on. When standing in front of the touareg facing it, as you look down the filter housing, you will see a small hole in the 8 o'clock direction. There is where a small tip on the filter element fits in. Make sure the two are aligned and with slight pressure, the filter should snap in.
7. replace the filter cap and tighten it.
8. replace the drain plug and tighten it. (I replace the stock drainplug with a magnetic unit I bought from ECS tuning)
9. put in 9 liters of motor oil.
The process is pretty straight forward. The only little surprise is that as soon as you loosen the drain plug the oil comes right out, not just dripping. A little messy.