To undeploy Mark 2, press and hold the top button for 3 seconds:
All 4 LEDs around the Arable logo will flash blue, then follow a counter-clockwise sequence.
To verify that the device is undeployed, view the LED indicator on the underside of the device and short-press the top button for 1 second. Yellow = undeployed.
If the LED indicator on the underside of the device lights green after a short-press, then the device is still deployed.