Once you have found the piece of production music that meets your needs artistically, and if you are very lucky also offers you cues of the right length (this can of course be a very time-consuming business), all you need to do is fill in the form and send off the cheque.
Beware, though, of thinking of production music as a cheap alternative to commissioning original music. Because the standard packages of rights that you can buy in production music may not be an exact fit with the rights you need, you may find yourself buying rights you do not need. It may cost no more to commission a composer, even to hire a small number of musicians and a studio; and doing