How to remove 1 Linux from 2?

Question

linux

Good day! I recently installed Linux Mint alongside Ubutnu. And so, I didn’t like Mint and I want to remove it.

I used to try to uninstall Linux by simply deleting the volume, but after uninstalling, every time I turned on the PC, the GRUB bootloader came out to me.

I wanted to ask, how to remove 2 OS correctly? (All 2 OS Linux) It is necessary that the data be saved.

Answer 1

I wanted to ask, how to remove 2 OS correctly? (All 2 Linux OS)

Format the entire disk (not partitions, but the disk).
You have made the right decision.

Answer 2

delete the partition with the system
later (update the bootloader
sudo update-grub
just don’t mix it up (partitions / disks), otherwise you will swear for a long time)))

Answer 3

If you want to remove the second OS, you must first ensure that the first OS is booted. Or using grub from the second OS, by writing the first one into its config, in order to then go into the first OS and restore its native bootloader.
Either by booting from the disk in rescue mode, mounting the partition of the first OS and making a chroot - also restore the bootloader of the first OS.