I havn't been able to find the VW tool. What I do instead is destroy the old one while removing it (usually)
To install the new one, use a Dremel Tool with the reinforced cut-off wheel to cut small slots in the two open ends of the clip. (it only takes a few seconds to do this) Then use a regular circlip tool to hold the clip-ring open. Sears sells an inexpensive circlip tool that has a screwdriver-type handle that holds the jaws of the tool open in one fixed position. It is usually in the automotive section, or next to the other, conventional circlip pliers.
The modified clips are SUPER easy to remove, as well.
good luck.
-tom