changing vendor, release tags

When I first entered my projects into cvs, I used import.  My
interpretation of the instructions that came with info, you were supposed
to cd to the computer:

$ cvs import -m "comment here" cvsdir vendor-tag release-tag

Where it doesn't really matter what vendor-tag and release-tag are.  Thusly
I used varied words for vendor-tag and release-tag.  Now I wish to
retroactively amend those project entries, and make it look like I had a
unified vendor-tag, and a unified release tag to start with.  How would I
do this?  I can see in the various ,v files a line starting with symbols
that lists the vendor-tag and release-tag info I used for that particular
file.  Can I just alter these with sed to my new ones, or will this break
something?

-- 

"Pay no attention to that man behind the curtain." - Oz the Great