Have a client where one user out of thousands is named
uid=bsmith,ou=nyc,o=acme

I am pretty sure in LDIF if I rename him to cn=bsmith,ou=nyc,o=acme that
will work.

Are there any prettier tools that can do that for me? C1? iMan?

I know how to write a toolkit rule to find all users set that way in the
tree in IDM, and fix them, but not sure how to do it more simply.