old unix guru
one further comment as to whether or not you actually need to replace the board.
I was having intermittent interference problems from other nearby bluetooth enabled computers. So I checked the signal strength and it seemed low. (you can do this by holding down the option key and clicking the bluetooth symbol in the banner, then you click on the device you are interested in). My BT speaker was at -68dbm (considered low) but was at -15dbm when it was at the same distance from my macbook 1.1 (i.e. white, plastic macbook). This is a huge difference (dBm is a log scale) so I replaced the BT board.
But after I replaced the board I measured again I got the same signal strength. I then checked it with another macbook pro and again I got the same signal strength.
So intermittent BT problems and low signal strength don't necessarily mean you need to replace the board. The macbook pro just doesn't have good BT signal strength, at least not compared to the old macbooks.
If you look closely with the screws (my eyes needed a magnifying glass) you will see that some of them have heads that are "stepped". hard to describe in words.
I just completed this repair successfully thanks to an excellent instruction and some help from iFixit support due to an error I made. A couple of comments that might help someone else:
1) make sure in step 15 that you TURN THE BOARD OVER and remove the tape from the bottom of the board. I "continued" removing tape from the top and then got completely confused when I couldn't find the screws in the next step. Yeah, it was my mistake because i didn't read the instructions carefully.
2) In step 15, leave the tape attached at the end of the bracket. this will make it much easier to replace the tape when reassembling.