...without removing those which are between the words?

That depends - on whether the hyphens between words have spaces, etc. between them. Also, optional hyphens can be deleted without worrying about the ' between words' issue, since they should only occur within words.

For example, assuming the hyphens between words have spaces, etc. between them, you could use a wildcard Find-Replace, where:
Find = ([A-Za-z])[\-^-]([A-Za-z])
Replace = \1\2
to delete both ordinary and optional hyphens within words.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]