remove MBR using DD

Understanding MBR size

Where,446 + 64 + 2 = 512

446 bytes - Bootstrap.
64 bytes - Partition table.
2 bytes - Signature.

dd if=/dev/zero of=/dev/sdc bs=512 count=1

ref: http://www.cyberciti.biz/faq/linux-clearing-out-master-boot-record-dd-command/