Open the Relay App to begin!
Under Direct Chats, tap on the Virtual Relay you would like to remove
Tap on Settings tab in the upper right
Tap on Remove Device
The above applies for Account Owners/Admins on the account.
Removing a virtual Relay does not stop the app user from logging back in if you are sharing a login. You would need to remove the profile from your account and then change the password. This would prevent them from logging back in.
If the profile you're removing from your account joined via you sending them an invite then they will automatically be logged out of the app and will not be able to log back without any further actions needing to be taken