Hi Constance -
You'll want to go to the Admin section of Cvent and then to Portal Users. Once you locate the Portal User that you are looking to delete, click on their name to go into their account information. You should then see a button to Delete:
If you are not seeing this option, you might not have the proper role to be able to Delete a Portal User. You may want to reach out to your account's Cvent system administrator for assistance or to Cvent Support to update your user role.
Hope this helps!
------------------------------
Rebecca Yousif
Senior Administrator - Event Technology
------------------------------