GMC 1999 Sierra 1500 Pickup Owner's Manual page 267

K2369
If your vehicle has wheel nut caps, remove them using the wheel wrench.
Use the wheel wrench and ratchet, with DOWN facing you, to unscrew
and take them off. Then take the hub cap off.
If the wheel has a trim ring, remove it by using the flat end of the wheel
wrench.
K2368
If the wheel has a smooth center piece or a center piece with recessed
nuts, remove
it
using the flat end of the wheel wrench. Place the flat end
of the wheel wrench in the slot on the wheel and pry out gently.
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