This article explains how to edit the access that an existing administrator has. 

Step 1: Click on Account > Admin Settings.

Step 2: Select the administrator whose permission you wish to edit and select the icon to view the existing permission that the administrator has.

Step 3: You may edit the permission based on their roles and click on Save Changes. (Please be noted that the editing of permission can only be done by Primary Administrator)

Step 4: Administrator permission has been updated!