Brilliant guide used this along with parts of the other guides here for 2017 Imac. Changed Sata drive to 2TB SSD and upgraded the factory 8GB to 32gb with 2x16GB Crucial Sodimm Modules (Part Number CT16G4SFS824A) which I can confirm work 100%. Whilst the Mac was in bits I also changed the PRAM Battery and had a general clean of fans etc etc. Makes sense to do it all when its apart as the less times you have to remove that screen the better! All in all took about 3 hours which also included 30 mins for finding where I had lost my isopropyl Alcohol too so as to be able to remove all the glue residue before refitting the screen. I would recommend buying the iMac opening tool, really does exactly what it says on the Tin and with the wheel being plastic It reduces the chance of damage to the edge of that screen but works extremely well in doing the job. If you are reading this and thinking of doing it then just make sure you have plenty of space so you can lay everything out in order as you remove it.