We currently have a NW5.1 tree/DS 7.60c with BM 3.7. We want to move
everyone to a NW6 tree/latest DS with BM 3.8. In the interim we would
like users in the NW5.1 tree to use the new BM. We don't use client
trust - users must log into BM login screen.

Is there any way to either synchronize users passwords across the two
trees, or give users an icon to click on and change their own NW6 password
manually before using the new BM?