editing an existing iso image

[Chad Skinner <cws-dls swbell net>]

I have a bootable iso image that have been asked to add an additional file
to. I can not remember how to do this will keeping the disk bootable. Does
anyone know?

Also, a while back (quite a while) someone said that an ISO image could be
mounted rw under linux and edited. While I can mount the fs rw it gives me
errors when I try to write to it. Does anyone know if this is possible.

Thanks,
Chad