Just to mention, be careful what drive caddy you buy, mine didn't work and I ended up putting my ssd in the regular drive slot. Now I have to wait until I can order the caddy again. Great guide mostly, worked out.
I don't know why some people are mentioning a torx. This is a regular phillips. Had one laying around from my old-style mac mini upgrade. It couldn't be easier. It's almost like the new style mac mini ram upgrade. So effortless.