Important: Removing ClickGUARD's access to your Google Ads does not stop your ClickGUARD subscription or TRIAL.
To remove ClickGUARD's oAuth access to your Google account, follow these steps:
Login to your Google account
Go to "Security" (link in the sidebar)
Scroll down to "Third-party apps with account access" and select "Manage third-party access"
Find ClickGUARD on the list and chose to "Remove Access"
If you're looking for information on how to remove ClickGUARD's manager access to your Google Ads, see here.
Read more on how oAuth access works here.