well I would have to say that the cheapest way to do it is to pay someone to do it for you. I offer this service and there are some others that do as well. Look at the for sale section of the forum. It all depends on where you live. If in the states i can help if some where else then i can help with that. thanks
Also one more thing. If you have a nand ps3 you will have to get a progskeet and that will have to be soldered. Also if you cant solder then you will have to buy the clips.
what is the model of your ps3? thanks