Tews - I install only the flanges without the pipe connected: it makes it much easier. I always buy new SS 6 mm nuts when I install an exhaust and put a tiny dab of anti-sieze on the stud threads.
By separating the flange from the pipe, you can easily install the copper gasket too. When all is in place, I attach the pipe by the springs, hooking the flange first, then pulling away from the motor. Wicked simple this way.