GMC 2008 Envoy - Manual (Page 378)

Removing the Spare Tire and Tools
The jacking equipment needed to remove the spare tire
is stored under the rear seat. To release the jack from
its holder, turn the knob on the jack counterclockwise to
lower the jack head. See Rear Seat Operation on
page 1-11 for more information.
The tools you will be using include the wheel wrench (A),
wheel blocks (B), extension(s) (socket end) (C),
handle (jack end) (D), and jack (E).
To remove the underbody-mounted spare from your
vehicle:
Notice: If you remove or restow a tire from/to the
storage position under the vehicle while it is
supported by a jack, you could damage the tire
and/or your vehicle. Always remove or restow a tire
when the vehicle is on the ground.
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