Removing a partition from an SD card is easy. You'll only need
* A PC
* The SD card
* A way to connect the SD Card to PC
Steps:
1. Connect the SD card to your PC and wait till its detected
2. Press the windows button / start menu and search for 'create and format hard disk partitions'
3. When disk Management opens, locate your SD in the lower pane
4. Right-click the partition you wish to delete and select 'delete'