Between the turbo and exhaust manifold there is a metal gasket and you can use it again, I have several times and have never developed a leak. If you simply unbolt the turbo from the exhaust manifold you can tilt it back some 3 inches, then put some duct tape on the turbo to keep the drilling fines out, then when done with the drilling for the pyro you can scoop the tailings out with your finger and follow up with a magnet to make sure you get them all. Good luck.
cheers, Kevin