I have an external drive with two partitions. I have deleted everything on the drive and I wish to make the two partitions into just one. But I cannot figure out how. According to articles on this I should be able to delete a partition by pushing the - symbol in the parition tab. But that option is greyed out. In disk utility the two partitions appear as two different disks of 2.2 TB and 801 GB and there is no obvious way to make one of them go away. I have enclosed a screenshot of how this looks in disk utility. Please help.