How to remove and EFI System Partition from a Hard Disk

If you have an external hard disk that has an EFI system partition (usually about 200MB) and want to remove it then this can be achieved by using DISKPART from the command prompt.

1. On the command prompt type diskpart
2. On the new diskpart prompt, type list disk. Note the Disk ### column.
3. Type, select disk ### (with ### being the partition you wish to delete. Usually partition 0 and with those 200 MB of size)
4. Finish by typing, clean.