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EaseUS or Minitool will work on your PC. I have used EaseUS and it did the trick while being very easy to use. Install whichever on your PC and it will walk you through the steps.
You can also use your rooted android device, if you aready have a custom recovery. You will need to boot the device to recovery (the process varies from device to device, but you should be able to find it in one of the android forums, like android central or phandroid), then using the recovery menu, select "Advanced", and then "Partition SD Card", then sit back and wait for a while for it to finish.
Make sure to back everything up before you start partitioning the SD card!