Having your Federal Pension direct deposited to your bank is pretty simple. Fill out the Direct Deposit Information Form, OPM Form 3206-0226. It's a one-pager. Be sure to sign it. Mail it to the Office of Personnel Management address on the form. That's it.
You can use the same form to have your pension paid to you via a Direct Express debit card. The Treasury Department doesn't want to send out paper checks anymore, so you pretty much will need direct deposit or the debit card.