Yeah, ready?
Unplug the joey from power.
Unplug cable from joey.
Plug joey into power.
When it boots, put in standby (hit power button).
Unplug from power.
Connect coax cable.
Plug into power.
Wait for it to boot back up, it should boot back into standby mode.
Nice, right? But after the last step it may still be in standby, power button turns it on, then it should automatically start a software download and reboot again, and be active.