and how to hijack nrf51422 with nrf51822 custom board using nrf51DK
and how to hijack nrf51422 with nrf51822 custom board using nrf51DK
have you tried the forum search feature which is just ^^^ up there at all? There are about 10 discussions a week about using debug out on the dev kits to flash other boards.
I recommend that you take a look at our Programming and debugging custom nRF5x devices blog post.