Prior to Jive 7 there was not a Run-As option where you could have centralized this process. In Jive 6, if memory serves me correctly you will need to execute API calls as each user, which is not ideal. It may be easier to just wipe the fields out from the DB and then spin the Jive instance back up. Unfortunately, given it has been far out of support for quite some time, I'm not sure I have many resources to link to besides this schema:
Hope that helps.