I just wanted to say that, in 2020, i used these instructions to replace the magsafe socket on my A1286, mid-2012, pre-Retina MacBook Pro. The internal layout is not quite the same but close enough for me to do the job. I skipped the steps of fully disconnecting the fans and speakers because of what others had said about breaking the sockets. it just meant I had to be extremely careful when lifting up the main board so that I did not tear and break the connections. I was able to disconnect the old magsafe socket with the board flat and in situ, but there was no where near enough room to be able to aline and press home the new par home. Reluctantly i had to lever up the board. This was difficult as there is a tapped post that holds a screw in the way close to where the USB sockets are, that prevented the board lifting up and out. I had to be quite forceful to manouevre the sockets out from the edge of the case.