Macbook Pro 2014 - update from Mojave to Big Sur - total failure - will not boot.
Tried to update Macbook Pro from Mojave to Big Sur. My machine is now unusable and will not boot. Hangs every time during update with apple logo and progress bar at about 35%.
Tried SMC reset, tried NVRAM reset, tried recovery mode, tried USB installer.
How do I get back to Mojave?
MacBook Pro 15″, macOS 10.14