Hummer 2005 H2 - Manual (Page 134)

To use the crossrail channels, do the following:
1. Use the included key to unlock the crossrail end
cap by turning it counterclockwise. If you ever
lose a key, your dealer will be able to help
you obtain a replacement.
2. Pull the end cap
straight out from the
crossrail.
3. Peel back the rub strip from the crossrail.
4. Slide the accessory you are using into the crossrail
channel and secure it as the accessory instructions
direct.
5. Place the crossrail endcap back on and lock it with
the key.
You will not be using the rub strip when using crossrail
accessories. When you remove any crossrail
accessory, be sure to reinstall the rub strip. To do this,
press the rub strip in place until it seats into the
channel of the crossrail.
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