When last year the motherboard on my 13" MBP from 2010 died the heat death of too much bed-work, most likely, I bought a used, identical machine and moved 256GB SSD, battery and (max) RAM and carried on like nothing had happened.
And it just kept on purring like a kitten from continual love and attention. But all hardware wears out.
After a while the battery from my first machine began the slow cycle death. Then I reinstalled the second machine's battery over and carried on.
2 days ago the trackpad began acting up - arrow darting all over the place, unpredictable clicking on everything, impossible to work on. Not knowing if it was software related I tried all the recommended tricks, but nothing. Ok, what the heck!
I came to ifixit to see if there was anything to changing the trackpad, and it seemed pretty easy.
Got a little routing by taking out the one in the original machine. Taking the trackpad out of the dead machine, removing the faulty trackpad in the live machine, putting in the old new trackpad - a total of about 10 minutes, tops.
And it seems to be working like it never did anything else.
Beware keeping you thumb as counter pressure on the trackpad top behind the screws, as you remove and re-enter the screws. The metal holding the trackpad in place is springy, but CAN bend.
And only remove the outermost screws on both sides of the springy metal. The middle two should just remain on the chassis..