Wanted to maximize the Wi-Fi potential of my MacBook Pro. The AirPort card in the mid 2012 RMBP was limited to 802.11n. So I bought the Airport card for a 2013 RMBP(802.11ac), and installed it.
Slow and steady wins the race here. Since all of the pentalobe screws are all the same size except for 2, I made sure as I took them out, that they go back the same way. Using a case I have for the MacBook, I used that as a reference of where they go, when it's time to put them back. You need to go slow to avoid scratching that beautiful aluminum body. Those screws don't give you much depth to really get a good grip. And you also don't want to strip them either. Also, you don't want them to know that you opened the forbidden fruit, and void any Apple Care warranties that may exist. Once inside, it was a glorious sight! Beautiful craft this electronic stuff here. I located the card, and it's tiny. First I flipped up the tape that says for "QualifiedApple Techs", and had a piece of electrical tape ready to throw under the pins, so they would not make any contact with anything. After I disconnected the battery, it was time to unscrew the lone screw holding the Airport chip in place. Once that was done, I popped off(carefully)the 3 antennae connections to the board. I carefully lifted, and tugged, and it came out smoothly.
I grounded myself to be on the safe side. I grabbed my new 802.11ac, Airport card, and set it in place. The hardest part was getting these tiny snap in place pins into their designated places. This took the most time. Once they were secured, I plugged the battery back in, then put the cover underneath, temporarily, just to make sure all was working well. Once I went to check this Mac, and saw my WiFi SSID and 802.11AC, after it, I was happy.
Next, check to make sure the Bluetooth 4.0 was working. So I tested it out on my iPhone & iPad. And it worked.
Once all was well, I went back in, and secured the black label tape over the battery terminal, made sure all was tightened, and put the cover back on. Thank God, that I had set all my screws to their designated places, it made it that much more easier.
Remember, slow and steady, you don't want to run your pentalobe screw driver over your cover of your MacBook, and leave a nasty mark there.
Once all tightened up, that was it.
Now testing the speed. It made a difference. Things definitely loaded a lot quicker. Download times were faster. Response to websites also. It's worth the upgrade if you can do it, and you have the patience.
The speed boost you get is worth it. That's if you have the proper devices. If your router doesn't support 802.11ac, then you'll have to upgrade. Also, your internet package, you have to have better than the basic 25/5 speed package, in order to really appreciate and take advantage of the new found time and speed you'll get with this simple yet easy, upgrade.