Any idea how to convert from UEFI back to Legacy Grub?

Any idea how to convert from UEFI back to Legacy Grub?

The kernel wants to do EFI boot and looks for grub.efi
and the article below fails to cover that issue.

(How to convert RHEL system from UEFI & GPT to legacy BIOS & MBR
https://access.redhat.com/solutions/767293)