EFI Partition Mistake: GRUB

[kumquatartist]

I installed Ubuntu to my external USB HDD, but I forgot to set the bootloader install device to /dev/sda. As a result, GRUB is installed on my EFI partition. Does anyone know how to get my EFI partition back to normal without cloning my Macintosh HD, repartitioning and restoring?

[LeopoldBloom]

I know this is old but here is another topic about it that may help if you still have issues or just want a solution for the future.

http://ubuntuforums.org/archive/index.php/t-476120.html

[kumquatartist]

Thanks, but that was a while ago, and I eventually resorted to using Carbon Copy Cloner in frustration. #-o