AD Change Domain

We run openfire on linux box but authenticate users through ms AD.

We recently have been acquired and need to change the AD location & domain.

Looking at the OpenFire admin console, seems to be as easy as go into ad settings and change the server and DN , however nothing is easy in IT world .

All users from forest A have been migrated to forest B with same usernames/pwds etc.

Currently users use forest A authentication but we would like to switch all to forest B, that way we can shut down forest A legacy.

Could you please advise what would be the best way of doing that?

Also am afraid of changing the AD as mentioned above and then lose the admin rights to login to console afterwards if something goes south.

One thing I keep on reading is.

Change setup in openfire.xml file to false, and redo the AD integration.

Would that be the best way to go?

What happens to Chat groups? Do those need to be recreated?

anyone ?