I've done this before and it was a moderate experience. So what happens is you set up a Paypal account, and add the prepaid card. Once that's done a small fee (around $2) will be charged on the card. The transaction description of that $2 has a 4 alphanumerical code which you enter to verify the card. Once done, the card is added and you are free to use as you wish; that $2 fee is returned to you.
It was a long experience for me because my card company didn't update the transaction list very often and I had to call them to figure it out and sometimes I got charged but the description never came through so I had to do it again, etc. Once you get it worked out all fees applied to the card come back though.