To revoke a user's access from the platform, go to ADMIN > USERS and select the user who you want to delete access for. 

You will then be taken to the USER SUMMARY for that user and at the bottom of the page, you will see the below options:

Please note: You cannot delete the user you are logged in as.

Once a user is deleted, you can still find a record of all users, included those who have been deleted, on the ADMIN > USERS summary page by selecting 'Include deleted users'. The status of users that have been deleted will show as such:

The username of any deleted user will still show in the relevant audit logs in the platform.