Download a Direct Deposit Sign-Up Form, also known as Form SF1199A, from the SSA website, print it out and then fill in the requested information.
Bring this form to your bank or, if you prefer, to your local Social Security office. Your bank or Social Security office should have this form available for you as well, so if you can't download or print it at home, you can fill out the form there.
Call the SSA at 800-772-1213 to make the change over the phone. You won't need to print anything out or visit your bank or Social Security office.