GMC 2007 Sierra - Manual (Page 374)

2. While continuing to
pull downward on
the push-pin,
squeeze and turn
the expandable end
of the push-pin
with a tool until it
releases from
the retainer.
3. Pull the push-pins
and lower dam
assembly away from
the retainers until
the lower dam
is free.
When you are back on roads, though, be sure to
replace the air dam.
Notice: Operating your vehicle for extended
periods without the front bumper lower air dam
installed can cause improper air flow to the
engine and may allow things like fog lamps or
tow hooks on the front of your vehicle to be
damaged. Always be sure to replace the
front bumper air dam when you are finished
off-road driving.
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