I have just got a new external hard disk, the Seagate Expansion 2 TB, and I am trying to format it to work on my Mac. I was told that I had to erase the disk and format it to OS X Extended (Journal) with the Disk utility program.
However, Disk Utility won't allow me to erase it, and the partition button is greyed out. I will attach some screenshots of the problem:
Any help is appreciated!