That’s it! You are done, a new drive will get created with your allocated space to that drive, and you can now use that space to store files differently on your external drive. After you are done, a finish message will be displayed by simply clicking on the next option. Now follow the guide to choose the size you want to allocate to that drive. Now right-click on unallocated space, and there select New Simple Volume.
Now you will see unallocated space left in the drive after you shrunk the volume, and this space will you now assign to a new drive. Now enter the storage in an amount that you want to partition in a different drive, and a simple click on ok. There you will see your external drive storage, right-click on it and select the shrink option. Now the disk management dialog box will appear.