In answer to installing grub2 on UEFI GPT:In brief, on an EFI-based system, you do not install anything in the  MBR; instead, you install a Linux EFI boot loader or boot manager in  the EFI System Partition (ESP) and set it as the EFI's default boot  program using a tool such as efibootmgr (in Linux), bcfg (in an EFI  shell), bcdedit (in Windows), or the EFI's own user interface.How can I do this step in the most risk free way possible?  I would want to install a Linux EFI boot loader or boot manager in the ESP and set it as the EFI's default boot program using efibootmgr.What needs to be backed up for a Windows 10 system prior to making this change?  The UEFI boot entries?GRUB 2 would be the typical choice for a boot loader?
how do I install GRUB into the ESP with efibootmgr?
grub2;dual boot;gpt;uefi