Administrators can easily delete a user from Review, Promotion, & Tenure from the User & Group Management page.
Log in to Interfolio and navigate to your institutional account
You may need to open the account switcher in the right hand user menu and select to switch to your institutional account.
Select "Users and Groups" under the Review, Promotion & Tenure section of the left hand navigation menu
Locate the user in the list and click the pencil icon to the right
Note that you can search for the user, sort the list of users by name or email.