Exhaust Replacement

[Nate Beck]

Hello all,
  I have a 85 coupe, and it recently has come down with a crack in the
exhaust manifold.  I was lucky enough to come accross a manifold and
downpipe from a 85 4kq and I wanted to put the manifold, and downpipe on my
coupe.  I have read Huw's page on exhaust, and I would like to do something
similar.  The question I have it this.  How hard is it to replace the
manifold myself?  The shop I went to said that they would replace the
manifold and the downpipe in addition to creating a 2.5" exhaust pipe with a
single muffler for about $525 if I supply the manifold and the downpipe.  Or
should I do this myself and just have them do the pipe and muffler, that
would cost me 125?  how hard is it?  I would assume that I would have to do
the following.

1. disasemble the intake manifold and remove,
2. remove the exhaust manifold and downpipe,
3. reattach the exhaust manifold and downpipe,
4. re-assemble the intake manifold and fuel injection.

I know that there is a lot of other little things involved also.

Am I missing anything here? or is does someone have a BTDT way that would
make it easier?

Thanks

-Nate

85 coupeGT (with a wheezing cough)