How to change account type on Mac
Step 1. Open System Preferences and launch the Users & Groups preferences pane.
Step 2. Click on the Lock button at the bottom of the pane to make changes.
Step 3. Enter your administrator password and then click on the blue Unlock button.
Step 4. Select the administrator account you wish to change back to a Standard user from the sidebar.
Step 5. Click on Allow user to administer this computer to uncheck the selection.
Step 6. Now click on the Lock button again to save and lock your changes.