Starting from the 2014 model, Apple integrated the RAM into the main logic board, making it impossible for users to upgrade the RAM themselves. This includes the 2014, 2018, and all M-series Mac Minis ...
I upgraded the RAM in my late 2009 Mac Mini from 2 to 4 GB. I used a pizza cutter instead of a putty knife to open the case. It was a lot easier than I expected it top be. Everything seemed fine until ...