there are a bunch of "clips" that hold the two peices together, you just have to bend them out of the way, and it comes apart.
I just recently bought a new one from Autozone.. no complaints so far (have about 3k miles on it). I would have rebuilt my old one, but couldnt source the re-build kit...
You can drive your car without the booster, just plug the vacuum line. I drove with mine disconnected for 2 weeks... just remember that you have to press HARD to slow down.