I found this procedure on the webs and used it slightly modified, as outlined below.
Become root with sudo su -
Insert the USB drive, and find its device name.
lsblk sdk 8:160 1 31.6G 0 disk └─sdk1 8:161 1 13.7G 0 part /run/media/gill/OCTD
Unmount the partition.
Run fdisk with the device name and remove existing partitions.