If you have a database connection to your WebFOCUS repository, there is a table named UOA_USERS that you can create a synonym for and query to get user information including their last login date and time. It also holds the status of the user (active/inactive) that you should be able to change to disable an account.
John Lewis's post in Is there a way to download the users and their last login date/time into a file similar to what you see on the security screen (WebFocus 9.1.1) was marked as the answer