What year of Civic is it?

I know on mine, you DO NOT need to remove the exhaust
manifold (a 98 LX). Also, on my 87
prelude, we didn't have to do anything like that to
replace the clutch. I could see at the very most that you
might need to remove the exhaust pipe, if it runs under
the trannie, but otherwise, if there is no interference
with the trannie side of the engine bay, I would not bother
removing the exhaust manifold.

Haynes and Chiltons are famous for telling you to remove
stuff so you can have easy access to whatever you are fixin,
but in many cases these steps just create a world of
frustration, as you are probably experiencing now.

A good example is when I did my Alternator (although this
repair is definitely not on the same level as a clutch
replacement), Haynes said to pull the driveshaft out to
gain access to the alternator. After looking at it really
hard, (and busting a ball joint from trying to take off
the driveshaft), I realized that there was a simple
mounting bracket that could be removed, instead of having
to drain the trannie, pop the ball joint, and pull the
drive shaft.

However, if you are really stuck on removing the manifold,
applying heat (carefully, there are some areas like the
head that you don't want to apply a torch to), can loosen
the most stubborn exhaust bolt.

Good luck,

t