Hi i have recently purchased an Imac 27 inch 5k 2014 edition. It has system snapshot installed so i have no option or cmd-r etc. I wish to erase the whole drive so i can backup and boot from my Sabrent Nvme enclosuse as I have never used my internal drive. I have no knowledge of terminal except diskutil list. I can strip an Imac down no problem but do not want to do this unless last resort ie remove hard drive.
any help appreciated.
any help appreciated.