GMC Yukon Owner's Manual page 241

UP Marking
,
DOWN Marking
One side of the ratchet has an UP marking. The other
side has
a
DOWN marking.
-
With the
UP
marking on
the ratchet facing you,
rotate the ratchet clockwise.
That will lift the jack head
a little.
If there is a wheel cover, pry at different points along
it's edge until it comes off.
Be careful; the rim-edge may be sharp. Don't try to
remove it with your bare hands.
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