In Terminal type the following command using the identifier found in the previous step and hit the Return key. diskutil eraseDisk JHFS+ MacOS /dev/disk1 The process normally takes a minute or two to complete.

If your internal, physical disk isn't disk1 then use the identifier as appropriate to your computer. Mine is disk1 here in this example.

The process normally takes a minute or two to complete. When the process is complete, you will see the following message: “Finished erase on identifier” where identifier was the number you previously identified.

The SSD has now been formatted as a Mac OS Extended (journaled) volume named ‘MacOS’. Continue using this guide to format the disk as an AFPS volume, however if a Mac OS Extended (journaled) volume is desired you may now stop.