Fixing a disk signature collision

I purchased two WD My Passport portable external hard drives recently. When I connected both of them to my computer, only one would show up as a drive.

Looking in Computer Management > Storage > Disk Management, the 2nd drive was shown as offline due to a signature collision. These are the steps I used to fix this problem.

1. Open DISKPART from the Windows Run command (WIN+R)
2. Enter the following commands:
3. list disk
4. select disk N
   Where N is the # of the offline disk
5. uniqueid disk
   This will display the unique ID of the disk
6. online disk
7. uniqueid disk
   This will display the new unique ID of the disk
8. exit