Thank you! Though that's easier said than done. I'm not sure how to do all that. Do I boot up the ext HD with the option key and go from there to erase it?
Erasing your external driver is easy
Boot from your internal drive (you cannot erase the drive your are booted from)
Launch Disk Utility
Select your external drive in the Disk Utility sidebar (the drive itself not a partition on the disk)
On the menu bar select Erase
Enter an name for the drive
Format: Mac OS Extended (Journaled)
Scheme: GUID Partition Map
Click the button labeled Erase
That will yield a clean drive with one partition. If you want to partition the drive then
Boot from your internal drive
Launch Disk Utility
Select your external drive in the Disk Utility sidebar (the drive itself not a partition on the disk)
On the menu bar select Partition
Enter a name for the first partition
Format: Mac OS Extended (Journaled)
Size of the partition.
Click the plus sign under the picture of the drive
Enter the name, format and size of the second partition
repeat steps 8 and 9 until you have defined all the desired partitions
Click the button labeled Apply
I wish you were upgrading your system to Catalina so you could format the external drive APFS and use Volumes instead of partitions, they are so much more flexible and you don't have to worry about how big to make them.
If we knew what it was we were doing, it wouldn't be called research, would it?
