If you want to change a user's permissions / user role, or you want to delete a user, follow the steps outlined in this article.
To find out how to add users read, how to add users to your account.
Reassigning a user
From the menu go to "Users".
Click on the three dots to the far right side of the user. Then click "Change Role".
You will see the following pop-up
Click on the drop-down arrow to choose from available user categories.
The user will be reassigned to their new role.
Deleting a user
From the User page click on the three dots next to the user you want to delete.
For an explanation of how different user roles work, read "What are user roles and how do I use them".