ok will do, also what would happen if the machine had a factory restore of the operating system, would i need to do this process again? silly question but i am going to sell my mac next year
Nah your question makes perfect sense. I'd want to make sure of the same thing.
In my opinion, a factory restore would revert to Mavericks, with files associated with the previous Airport/BT board that came in your 'puter. So you would have only one option: reinstall the original BT board, then do a full factory restore.
This upgrade is meant to work with Yosemite, and if you aren't restoring to Yosemite, then the process would not be applicable.
With that said, I am certain since this BT4.0 board DID COME in 'puters that shipped with Mavericks, that it would be simple to re-convert this process for Mavericks, to the BT4.0 board. BUT, that would be more work than just simply re-installing the original board, in my opinion, and relatively pointless since you wouldn't get any additional features for your effort.
I believe (someone please correct me if I am wrong) that what I said above would work, but the order of operations could be wrong. I assume that the original board would have to be reinstalled prior to the factory restore. Doing it the other way around would result in potential problems. But hey, Im no expert.