So I've figured out a really tedious way to do it.
Go to Window > Show View > Other > Navigator .
With the navigator open, and the project open, right click and choose "Move" to move the files temporarily to my computer's harddrive.
Then, after moving all of the projects one at a time, change the drive letter of my external using Administrative Tools from my Control Panel.
The move all of the projects over to the new location one at a time.
What a headache.