parted /dev/<devicename>
mktable -> Table type: msdos -> Destroy data: yes -> quit
fdisk -s /dev/<devicename> --- This gets the blocksize of the device.
Make the last five digits of this number zeros. Example: fdisk -s /dev/sda Will show an error about GPT, and then the block size: 39078144 Change to 39000000 which equals our blockcount
dd if=/dev/zero of=/dev/devicename bs=1k seek=blockcount dd if=/dev/zero of=/dev/devicename bs=1k count=20
dd if=/dev/devicename of=/dev/zero bs=4k
sgdisk -z /dev/sda