Yes you can replaced the keyboard on a Macbook Pro Unibody. In fact, I have successfully replaced several. However, it does require patience and the hands of a surgeon. I'm really not sure why some of you "Professionals" who suggest that it is impossible when all of you know that it is very possible to replace the keyboard on a Macbook Pro Unibody. Guess you guys need to sell top cases.
"As far as I'm aware all 15"" unibody use identical keyboards (same model number of computer since 2008). Maybe 2012 model different. That said I was able to remove milk from 20-25 keys using an x-acto knife a very pointy tweezers and ""canned air"".
The problem with these keyboard and impossible to repair is that the three layers of plastic are glued together! In the old days you could peel apart the layers and clean with dish soap and re assemble.
If you have fewer than 10 affected keys it would be worth the effort of a top-side fix as long as you realize the risk of needing to use an external USB keyboard while the replacement comes should you break it.
If you look at any single key contact you can see the two layers with the crossing traces going to the center. The process to clean out the milk etc. is this:
On the TOP LAYER, determine the direction of the trace, example horizontal. Now make two in incisions on either side of the center cutting in that same direction on either side of that trace. Cut through top layer only and INSIDE the AIR BUBBLE surrounding the center. Now use the likes of a SEWING NEEDLE to lift up the top layer between the slits. Next use canned air to vamoose the contents in the air pocket mucking things up. In my case it was milk. If its thicker like oil you may likely need to use a solvent to flush it out.
I had 100% success with the 20+ affected keys. Took a couple hours. Sadly a cat knocked a whole glass of water on same fixed keyboard 6 months later and killed it.
If you manage to kill your power switch I have a ""jump start"" process. I have a YouTube video showing how."
"I have done this repair several times. I had somebody say that apple did it for them for $130 but now that I think about it, that HAD to be pre unibody!
When i replaced my own keyboard, I put tinted tape over different groups of keys (yellow alpha, green numbers etc). De-tunes the brightness and makes the mac much more eye friendly.
It's a shame that the film layers on the new keyboards are glued together. I've repaired about 10 keyboards in the past without having to replace by separating the layers and cleaning them.
Usually if liquid gets into MacBook Pro keyboard it will dissolve traces or the ""glued"" interconnects making the keyboard a total loss.
Fortunately. $35 and an eBay account will get you a new one.
Unfortunately a ""level 8"" difficulty of repair. Almost impossible to avoid stripping one of the 60 or so screws. One of the ones on the keyboard I just removed had only 40% of the screw indent making it nearly impossible to remove. Use a good set of hardened steel bits!
-awr
Update
See my markup:
the blue lines are the wire traces you can not disturb.
your best bet is to separate the films where the purple arrows are; get a needle, or x-acto point between the three films of plastic; doesn't matter if between 1 and 2 or 2 and 3 layer. insert on both top and bottom where purple arrow are and then use a 'canned air' to blow the liquid out.
unfortunately there is a good chance that if a 'string' of keys are out, what has happened is that the trace is actually damaged between the layers, where it was 'glued' together.
I had over a dozen keys that didn't work properly but sometimes worked because milk got in there, and on the model of computer, the films were more solid, so i had to cut slits, but in your case, you can see the EDGE of the film sandwich, so you can peel them apart (they are glued), just enough to get an air blast in; if you pull too far you risk tearing the fragile silver trace .
Yes they're selling keyboard on eBay. Unfortunately you can't replace them on the 13" Unibody Macs. The keyboards are so emplaced that removing them without tearing the top is impossible. You have to replace the Upper Case. We would need to know your exact machine to direct you to the exact keyboard.
So basically, officially, and easily, you cannot, however if you think you're at the right skill-set, and have the time/patience, then use the teardown and try to do it yourself. You'll probably also be voiding warranty, so unless you're rather experienced and not under applecare I wouldn't suggest you do it.
