Howto Remove An UCS Master From An AD Domain
Note The following is a rough sketch, not a detailed procedure description. Use at your own risk an match to your environment.
Step 1
Remove the AD-connector app from your UCS master server
Step 2
Unset all ucr variable related to *connector/ad*
Step 3
Delete the computer account on Windows AD (same name as the UCS server)
Step 4
Re-install Ad-connector app and configure from scratch.