I have a 2001 Forester that I bought new with 101k miles and the check
engine light has been coming on since 91k. I've taken to the dealer
twice (91k and 101k) as well as a independent shop (97k).  The dealer
replaced the Knock Sensor and cleaned the Air Assist Valve (91k).  The
independent performed an Air Induction Service (97k).  When the check
engine light came back on less than 2 weeks after having it in with the
independent, he didn't want to deal with it anymore but said that
perhaps the "cat is showing it's age". I took it back to the dealer with
101k and they now claim that the catalytic converter needs to be
replaced but want $1050 for it.  I called an independent exhaust shop
and they quoted me $550.  For what it's worth, the Front O2 sensor was
replaced under recall at 81K.

My questions are:

1 - How hard is it to replace the catalytic converter?  Do I need
special tools and I'm guessing getting the bolts loosened may be a
chore.  Will I need a manual and do you have a recommendation?

2 - Where can I get parts?  I called an Autozone and Advance Auto Parts
and neither of them carry the parts.  I have yet to try the dealer but
have looked online and a few places claim they have them in the $300
range.  Do you have to get any gaskets, etc or do these come with the
part when you order.

I appreciate the feedback because saving $700 from the dealer if it's a
few bolts I need to turn would make me very happy!

Thanks,
Bill