Slash User Access (dbo rights)

Hello,

Back in 2009, we would grant dbo rights though a SQL command which would result in sysusers having slash \AADD\UserName accounts. if we queried sysusers at the database level, the results shows \AADD\Username user mappings.

Does anyone know of a SQL commend that will remove these old legacy aliased "dbo" network accounts from sysusers?

Any help would be greatly appreciated.

Deb