I think you got things reversed ;-)
The hard part is getting the display off without damaging it. Just in the process of pulling it can kill it which would be an expensive mistake.
Follow the IFIXIT guides to the letter and use the correct tools. For starters you need the iMac pizza cutter iMac Opening Wheel as well as two sets of these Plastic Cards and I also find these help as well iFixit Opening Picks (Set of 6)
Dont forget you’ll need at least one set of [リンクされた製品が存在しない、もしくは無効: IF174-005] I would get two sets to be safe.
Now the hard part, which drive are you planing on installing? Swapout the HDD for a SSD, or put in the Blade SSD?
Hold on here! If you have a Fusion Drive you’ll need to do first break it before you can alter anything. Follow this guide: How to split up a Fusion Drive
As to which drive to alter. The rub here is you’ve got your self boxed in ;-{
Given the amount of work I would buy the proper blade SSD for your system while a bit more it will make a BIG DIFFERENCE!!
I try to get people to go with a dual drive config whenever possible. What I mean here is a SATA HDD or SSHD for the deep storage (1~2 TB) then a PCIe/NVMe blade SSD which is the boot drive with the apps and cache/paging space for the apps. I go with at least a 256 GB blade drive. If you are doing music, photo or video editing you may need a bigger SSD.
I don’t recommend keeping the teeny tiny SSD Apple give you for a Fusion Drive if you upgrade your SATA drive to a SSD as its just too small to be useful.
So lets review what a Fusion drive is… You have a 1 TB SATA HDD and a blade SSD (any size) your effective storage is still only 1 TB !!
The SSD is only a cache drive to make a copy of the more used files for faster access. True, a bigger SSD gives you a bigger cache but is it really useful? Don’t forget Apple learned a cache drive setup can be very hard on the SSD so the small SSD you see 24 GB is really a 32 GB drive! It’s just way over provisioned to offset the high wear the SSD gets. So is this really such a great idea?? Remember SSD’s wear for every cell alteration unlike a HDD which mechanically wears out but rewriting a track can be done over and over again without wearing!
So why do you want to cripple your beautiful 5k iMac system with a PCIe/AHCI 2.0 x2 SSD instead of a PCIe/NVMe 3.0 x4?
Review this great guide: The Ultimate Guide to Apple’s Proprietary SSDs
Here’s the drive you want 256 GB PCIe 3.0 x4 or if you can swing it 512 GB PCIe 3.0 x4
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