Go to https://www.mediafire.com/myaccount/accountbilling.php (make sure you are logged in!)
If you have a free account, click ‘delete account’, enter your password and you are set.
If you have a pro account, cancel all subscriptions by clicking the ‘cancel subscription’ button. Once the pro subscription period is over, your account will become a free account, and you can take the steps mentioned above to delete it.
URLS:
Please note that AccountKiller.com is not associated with the business listed on this page. AccountKiller provides easy-to-understand instructions and guides on how to cancel charges and relationships from the list of businesses on our site, we have no affiliation with these businesses.