Booting into recovery mode on a Mac usually requires rebooting the computer and holding option + R. There are times where option+R is not working on certain keyboards, usually a Windows keyboard. To boot into recovery mode on a Mac having this issue:
- Open the terminal
- type: sudo nvram internet-recovery-mode=RecoveryModeDisk && sudo reboot
- Your Mac will reboot into recovery mode
Once in recovery mode, make any necessary changes. When done, reboot the Mac to exit recovery mode.