Check that the money order amount is correct. Go to any Post Office location.Take cash, a debit card, or a traveler's check. Fill in the recipient's name. I'm here to show you how to cash in a Western Union money order and we'll walk through the steps. In the "Pay to" or "Pay to the order of" field, write the name of the person or business you are paying. To fill out a money order you need to first fill out the who the payee is, the purchasers information and sign it.