DON'T remove the Battery Cable, you risk the battery NOT being recognised when you start the Mac up again, or breaking it!! More to the point, APPLE DOES NOT RECOMMEND THIS, so don't do it! I Installed 2x 8GB ( 16Gb total) of Crucial Mac RAM at 1333Mhz for my Late 2011 MacBook Pro, and it works beautifully, fully recognised and working well. I followed these instructions, but as Apple didnt recommend disconnecting the battery, I skipped this step, and as well as taking less time, nothing was damaged or broken, and everything works perfectly!!! Just make sure that you DISCHARGE ALL STATIC ELECTRICITY FROM YOUR HANDS, by touching a metal surface in the Mac. Apple recommends the edge of the Optical Disk Drive ( Big silver thing ) before touching any parts. Also, Take care removing the RAM out of its packet, DO NOT touch the Gold connectors, and hold the RAM by the edges. Finally, be PATIENT, GENTLE and it should all go perfectly. I managed it first time, with no technical ability, so follow my advice. Good luck!