I know almost nothing about computer repair. I'm an elderly woman who is partially blind. I did find a step by step guide on iFixit and have a friend with tools and nimbler fingers than mine. He's not familiar with Mac's.
This is model iMac14,1 late 2013.
My problem is: How to get a functioning OS on the new drive so I can clone my old drive onto it.
I CANNOT install the latest Mac OS. If I do (I think) I won't be able to clone my current OS (High Sierra) backwards over it. Most of my important apps and games aren't compatible after High Sierra.
There's a 20$$ Mountain Lion OS in the Apple mac store, but I don't for sure know how to install it on the iMac - the Mountain Lion OS is a download. Do I have to borrow a dvd player and burn a disk, and use the dvd player for an install - or is it good enough to have the dmg on my current peripheral drive?
Will this even work? 1) Have a OS ready on the new internal drive, 2) clone (Carbon Copy Cloner) my current working OS - I'm booting into it on a peripheral drive - over the new OS on the new drive.
I know - so many questions. If you have advice, I'm grateful.