B pipe replacement and rusted nuts
 

Hello. I have a 1995 Accord Ex (F22B1) that needs the B pipe and
muffler replaced. I have the required parts and gaskets, but am having
a problem removing the nuts that connect the existing cat and B pipe.
The nuts are substantially rusted, and I don't have a metric or
standard socket that will fit securely over it. The nut appears to be
13mm, but the rust is preventing the socket from fitting over it.

So, what is the "standard" procedure for removing these nuts? Muffler
shops must deal with this every day. Most of the rusted bolt/nut
threads I've read seem to either say "cut it out" or make the
assumption that you can get a good socket over the nut or bolt head.

If I can't figure this out I think my only option would be to replace
the cat and B pipe as a single unit since I can't seperate them.
Hopefully someone with experience can help me out. Thanks in advance.