Depending on the year and model of the attachment points are different.

Front bumper

scheme of fastening of front bumper Chevrolet TrailBlazer (2001-2009)

 

scheme of fastening of the radiator grille of the Chevrolet TrailBlazer (2001-2009)

 

Rear bumper

diagram of rear bumper Chevrolet TrailBlazer (2001-2009)

 

How to remove front and rear bumper Chevrolet TrailBlazer (after 2013)