Delete GRUB after deleting Ubuntu from Mac Dual Boot

My question is a bot specific. I installed Ubuntu 12.04 on my MacMini (Mid 2010) and deleted it after some problems. I resized my Mac Partition so that there was no Ubuntu Partition anymore. But it seems, that I installed GRUB in a different section. If I am starting my Mac I am getting in a GRUB menu, there I am typing "exit" and my Mac is booting for about 5 minutes (very slow!), but later its working fine. But I woud like to deinstall GRUB now. Some people say its dangerous... Is there a safe way? Thanks!

Much faster and safer solution.

Boot OSX and in the terminal run these commands:

mkdir mnt
sudo mount -t msdos /dev/disk0s1 mnt

You will see a new drive "EFI", open this drive and open the folder "EFI". Inside you will have the folders "APPLE" and "UBUNTU".

Just delete the "UBUNTU".

Restart and enjoy!

It seems you have installed grub to the MBR, which is emulating a legacy boot and causing the slow boot times. The only way I found to remove grub completely on my mbp 5,5 was to boot the recovery partition (hold alt at boot) then do a complete reinstall of OSX from there. Remember to erase and reformat the entire disk, as this will generate a new MBR.

If you don't have a recovery partition then boot into OSX, then create a recovery disk/usb using Apple's utility found here.

If you do not want to reinstall your system you can change the bootloader to refind, which can be found here. This should get your mac booting in EFI mode once more.

Good Luck.