MBP Boot Help

Start up from macOS Recovery: Turn on your Mac, then immediately press and hold these two keys until you see an Apple logo or other image: Command (⌘) and R. 

If asked, select a user you know the password for, then enter their administrator password. 

From the utilities window, select Disk Utility and click Continue

Select Macintosh HD in the sidebar of Disk Utility. Don't see Macintosh HD?

Click the Erase button in the toolbar, then enter the requested details:

• • Name: Macintosh HD
  • Format: APFS or Mac OS Extended (Journaled), as recommended by Disk Utility

Click Erase. However, if you see an Erase Volume Group button, click that button instead. After the erase is done, select any other internal volumes in the sidebar, then click the delete volume (–) button in the toolbar to delete that volume.

During this step, disregard any internal volume named Macintosh HD or Macintosh HD - Data, as well as any volumes in the External and Disk Images sections of the sidebar

. 

Quit Disk Utility to return to the utilities window.

1. If you want to start up again from the disk you erased, select Reinstall macOS in the utilities window, then click Continue and follow the onscreen instructions to reinstall macOS.

If Disk Utility reports that the erase process failed, your Mac might need service. If you need help, please contact Apple Support.

Or if reinstalling fails contact Apple Support