rotor and wheel mounting section separate?
 

Will the rotor and the piece in the middle separate? I cant get them apart. My machine shop screwed up the piece the wheel mounts to.. Can I buy just the center section? And how do I go about getting it off? Heat?

The hub? The rotor comes off the hub in the front, but you have to take the hub off and undo the bolts that hold the two together. The rear rotor is a one piece.

its off the car, but the hub will not budge from the disc?

Front or rear? Sounds like you're describing the front. The hub (the part the wheel mounts to) is bolted to the rotor. Once the bolts are removed you may need a rubber mallet to knock the rotor away from the hub. If you're machine shop screwed up your hub, it can be replaced.

yeah its the front, Ill see what I can do.

Where could I buy a new hub?? Are they expensive?

Rust binds the hub to the rotor. Shock it with a mallet like Jon said. If that doesn't work, use a 3 pound sledge or equal. Don't beat it to the point it dents or warps the rotor, but just shock it.

Your best bet is to buy a used hub. There are plenty out there. Post a WTB ad in the Classifieds.

I just did this... I put two 2X4's on the floor, spaced so the rotor sat on them but the hub did not. Then tapped out the hub.

Call any Porsche dismantler (like Parts Heaven) for a used hub.

^thanks I got it and 2 rebuilt front calipers for cheap!