To manage your memberships, check that you're logged in to your account, and then go to Email and Notifications under Account.
Next to each Group, you'll see links to:
If you remove yourself from a Meetup Group, take heart! You can always find a new one. Just go here to search by keyword for anything that interests you, wherever you are.
If you would like to remove or delete your account completely from the site and fully unsubscribe, you can do so from your General page under Account.
Click there and scroll down to the bottom of the page where it says Delete your Meetup account. Be careful, this is permanent!