My original 500GB hard drive was very SLOW .
Super easy. Followed the instructions provided on ifixit.com, easy to follow and step by step. I was up and running within an hour. Now my Mac Mini is FAST!!
1. Backup to Time Machine First - restore is fast and easy.
2. Follow the instructions for a complete and clean install of MacOS
3. BUY THE TOOL KIT and logic board removal tools! The ifixit toolkit is complete and makes this job a breeze!
4. Lay everything out on a large piece of poster board or cardboard, with a sharpie, draw a circle for each screw and outline of each part - makes putting everything back together a breeze!!