This bluetooth adapter. Since this link will probably be dead relatively soon it might pose a problem for those of you trying to do this mod; the item is listed as a generic bluetooth adapter but in the manual it is revealed to be the BTAV101 manufactured by Flaircomm.
A few lengths of thin wire. I harvested my wires from an old parallel cable.
So, let's get on with it.
UPDATE:- After getting it all together and trying it out it turns out that the mini's case doesn't allow the transmitter to work nearly as far as it normally would. Extending the antenna out of the case doesn't help. It works up to about 6 feet when out of my pocket but it starts getting choppy while in my right pocket. Not sure what's causing the interference in my pocket, but the problem disappears while in my left pocket.