GMC SIERRA CK2 1999 Owner's Manual page 270

With the UP marking on the ratchet facing you, rotate
the ratchet clockwise. That will lift the jack head a little.
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Then take off the hub cap.
If the wheel also has a trim ring, use the wheel wrench
to pry along the edge and remove it.
If the wheel has a smooth center piece, place the wheel
wrench in the slot on the wheel and gently pry out.
If your vehicle has
wheel nut caps, use the
wheel wrench and ratchet
to remove them.
Turn the wheel wrench
counterclockwise,
with DOWN facing you,
to remove the
wheel nut caps.
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