Julien,
How easy it is depends quite a bit on the translation
company's process and what file types they'll deal with. For
example, our in-house translation group has software (WorldServer)
that pulls strings out of Word documents, HTML files, PowerPoint
presentations, and others. But they have to have a filter for each
type, and new file types require new filters. If the company you're
dealing with takes HTML files and gives you HTML files back, you're
most of the way there.
I give our translation group my HTML topics; they translate
and send them back. Then I drop them back into my project using
Windows Explorer and tell it to replace the old ones. But that
works because I have a copy of a project for each language. So far,
it was worked pretty well--maybe a glitch or two, but nothing
major.
When it comes to files like the TOC, glossary, and index,
your best bet is to have them look at those files first to see if
they can work with them. If not, you may have to copy the text you
want translated into a more friendly format for them. Then you'd
have to copy/paste the text back into the RH files once they're
done.
Hope this helps,
Ben