The gasket is reusable. No problem. Expect quite a bit of trouble removing the downpipe from the turbo housing -- it's a bear to get to it. I had a good muffler shop do the install of the TurboXS DP and MP. I know the guy so I watched the process while the car was up on the lift.
So, if you do this yourself, the instructions and photos here will be a big help, but expect this to take some time. Be patient.
BTW this is a HUGE performance increase. Probably better than anything else you can do for the money. And be prepared to start getting a CEL light after a few miles. I'm putting the spark plug extender fix in tonight to raise the O2 sensor further out and away from exhaust flow and see if that takes care of the light.
I'm new to the forum. Been lurking for a while, but have played with turbo tuning (mostly in SAAB's) for quite a few years.