Cancel Website Account
You may need to cancel a user's website account if there are duplicate accounts for the same user.
Take care not to cancel the website account which corresponds to the user's correct contact record in Salesforce.
1. Search for the user
In the Manage menu, select People. The People page is displayed.
Search for the account using the fields at the top of the page and click Filter.
2. Cancel the user's website account
Click the Edit button next to the account you wish to cancel.
Scroll down to the bottom of the Edit page and click Cancel account.
A confirmation page is displayed.
Select the method - 'Delete this account and its content' to cancel the account and click the Cancel account button.