How to replace the hard drive in iMac 27″ and iMac 21.5″ Retina Display?
Hard drive replacement requires taking Retina display off from the iMac. Before replacing hard drive on the iMac 27″ and iMac 21.5″ you need to have ESD safe mate, ESD wrist strap, screen glue cutter, special Torx screw drive, and sometimes heat gun may require.
Caution: Things may go bad if not done properly such as Broken screen, a short circuit on the logic board, getting shocked from the power supply.
1. Unplug the iMac
Shut down the iMac and Unplug the Apple iMac. Place iMac on the ESD safe Mat and wear the ESD wrist strap. Press the power button for at least 30 sec to 2 min.
2. Remove the Display Adhesive
Remove the LCD adhesive with the iMac Adhesive Cutter. You may need to apply some heat on the edge depending upon the condition.
3. Remove Flex from LCD to Logic Board
Remove two flex that is coming from LCD to Logicboard. Do not widely open the LCD
4. Remove and Install Hard Drive
Remove old hard disk drive from the iMac. You will need T10 Torx Screwdriver to take out the hard disk drive. Install new SSD on to the same place.
5. Install New Mac OS X
After installing SSD and LCD back to the housing of the iMac. Finally, its time to install a new mac OS X on the new SSD. You will need bootable USB with mac OSX in it.
How to Minimize the risk of breaking the iMac?
Go to the professional who is doing this for many years. Instead of an expensive DIY project.