Use your trampoline to jump on top of the giant candy cane at the
top of the room. Walk to the right and flip the machine switch to
off. This works for both machines.
Get a running start. Then, when you're near a cliff, simply let go of
the control pad. The Boy slides. If he slides off the cliff, you'll be
able to make him run back onto the cliff, or if you want him to look
down and fall, don't touch the control pad at all.