Go to http://www.1up.com/my1up/settings and tick the boxes next to ‘Delete my account’ and ‘Delete my account and data’ and click ‘save’.
You might think your account is now automatically deleted, but it’s not. It’s more like you have now sent a notice to the website administrators to have your your account deleted. What happens next remains to be seen. We didn’t check yet if the account really gets removed.