HOW DO I REMOVE macOS High Sierra 10.13.4
remove High Sierra
MacBook Pro 15", 10.14
remove High Sierra
MacBook Pro 15", 10.14
You can easily fall back to your previous macOS with your Time MAchine backup.
Restore your Mac from a backup - Apple Support
You can easily fall back to your previous macOS with your Time MAchine backup.
Restore your Mac from a backup - Apple Support
Why do you wish to remove it, and with what do you intend to replace it?
HOW DO I REMOVE macOS High Sierra 10.13.4