Upgrading Ram on Late 2015 iMac Retina

Back in 2017 I purchased a refurbished late 2015 iMac MK482LL. It's still going on strong for what I use it for - mainly development. It came with a 27" screen, 2TB Fusion drive, and an Intel i5 3.3GHz quad-core CPU. The Fusion drive truly makes a difference and the 2TB model has a larger …