Guys, I hope someone can help. I've read lots of comments about certain machines not being upgradeable, and others needing adapters for SSD's to fit. Question is - is the 512gb, factory fit SSD hard drive on my early 2016 15" Retina MBP upgradeable to a 1 TB version? Will any particular one/physical size be needed? My machine is fitted with 16gb of RAM and I'm guessing that part ISN'T upgradeable , nor can the machine make any use of more RAM? Thanks for any comments.