How to uninstall add-ons

From Google Sheets & Docs

Go to Add-ons > Manage add-ons in the Google Sheets/Docs menu:
A special menu to manage your add-ons.
Find the add-on of interest in the list, click the icon with three dots at the upper-right corner of its image and choose Uninstall:
Delete add-on from your Sheets/Docs.
The next window will ask you to confirm the action:
Confirm if you want to remove the tool.
Do so by hitting Uninstall app and the add-on will disappear from the list of your tools:
The button changes one the add-on is removed.