GMC 2008 Yukon Denali Owner's Manual page 422

8. Tilt the tire toward the vehicle with some slack in
the cable to access the tire/wheel retainer (G).
Separate the retainer from the guide pin by sliding
the retainer up the pin while pressing down on
the latch.
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Once the retainer is separated from the guide pin,
tilt the retainer and pull it through the center of
the wheel along with the cable and latch.
9. Put the spare tire near the flat tire.