[gchappel]

You need Porsche tool # 911.33.235.9 which costs 47gizzilion dollars.
The speedometer is acutally just pressure fit in, and if you can get a good enough grip it will come out. The first time I pulled mine, I covered the tip of a screwdriver with a layer of electrical tape and used that to carefully pry the speedo loose. If you are careful, the tape gives enough padding so that there are no telltale marks when you are done.
good luck