To manage your users, click on Users in the main menu:
On the Users page, you can:
click on the plus icon:
You will be taken to the "User create" page. As a minimum, you must enter:
Click on the view icon (eye) for the user to view their details:
You have an option to edit the user on the form.
Click on the edit icon (pencil) for the user to edit their details:
Click on the delete icon (trashcan) for the user to edit their details:
Edit a user (see above) and on the edit page, set the "Active" status to "False" and save the user:
The same above, but set the "Active" status to "True".