My solution would be to delete the partition with the WD software on it, then expand the other partition to fill the whole disc.
To do this call up Windows Explorer
Right Click on This PC (may be My computer).
From the context menu select Manage computer.
A window will pop up divided into a left and right section.
In the left section select Storage/Disc Management
After a pause while the computer looks at the discs, the right hand window will display a list of your discs and their partitions. Be very careful at this point NOT to mess around with the main disk, which will probably have partitions call C: and Recovery.
Select the western digital drive by clicking on it.
Right click the volume that you want to remove
From the menu select Delete.
You will probably have to confirm
Right click the other volume
Probably select all the available space, not sure as I do not have a disc to try it on.