Great tutorial. I would add two comments. Firstly between steps 14 and 15 there is a cable that needs to be unconnected (see other tutorials where it is detailed) - it needs to be "walked" out, and you ned to remember to reconnect this. Secondly when putting the logic board back in be sure not to trap any of the connectors underneath it. It is a real struggle! I ended up undoing the 6 screws that hold the main battery assembly in and lifting this slightly to give me space and allow me to reinsert the ribbon cables on that side of the board. The reason I needed to disassemble my laptop was that it kept going into sleep mode, sometimes every few seconds. Apple wanted to charge £550 to fix it. I found the problem was with the micro-switch that detects if the lid is closed (it would work fine in clamshell mode). Switch is between the thunder port and USB sockets. Sprayed with contact cleaner, isopropyl and antistatic spray and dried with hairdryer, been working a treat since! Cost of a pentalobe driver!