Gparted works well enough, last I checked. Just delete the partitions, and the space will be freed to make a new partition from that reclaimed space. You will have to remind the bootloader or reinstall the bootllader to be able to properly default to the OS you want.
Gparted works well enough, last I checked. Just delete the partitions, and the space will be freed to make a new partition from that reclaimed space. You will have to remind the bootloader or reinstall the bootllader to be able to properly default to the OS you want.