If you no longer wish to be a seller but would like to continue buying on BrickLink.com, you can reach out to our help desk and request that your store is unverified. This will remove your selling capabilities, update your account to ‘buyer only’ status, and hide all your store information.
Before you can revert:

All your orders must be in Completed or Cancelled status. Visit Orders Received to check the status of your orders.
Any outstanding balance on your account must be paid, so that the amount owed is $0.00. For more information, visit your My Fees page.

If you change your mind after reverting from a seller to a buyer and want to become a seller again, you can upgrade from a buyer to a seller on the Registration page.

Seller to Buyer Revert