how do I change my catalytic converter?

How hard would it be to change my catalytic converter? 

is your car a 1.8 or 2.8?

http://www.audiforums.com/m_755733/tm.htm    (does not specify)
http://audizine.com/forum/showthread.php?t=101953     (1.8t)

It's a 1.8 liter

the second link suprA4 posted. the cat->dp bolts are the biggest PITA. soak them in pb blaster the night before you start this and be prepared to curse a lot

well there many DIY for the 1.8t but if you have the 2.8 your better off getting aftermarket cats an djust cutting and welding them on, the cats are conntected fromt eh downpipe (starts right after the exhaist manifold) and goes all the way down to the y-pipe which can be a PITA to get off, all in all look at about 400 minimum for the cats (each) and about 3-500 in labour.

If you do decide to do it by yourself make sure you have u-joint extensions, the cat to downpipe is no bueno, and when u do get that out my advise to you is put the testpipe and downpipe together before you install it, it makes life a lot easier.

cat*