Below are the procedures to fix the bumpers. Arrows indicate the location of the screws, nuts and caps.

Front bumper

 

the scheme of fastening of the front bumper of the Chevrolet Impala (1999-2006)

the scheme of fastening of the front bumper of the Chevrolet Impala (1999-2006) 

the scheme of fastening of the front bumper of the Chevrolet Impala (1999-2006)

 

Rear bumper

diagram of rear inner fender Chevrolet Impala (1999-2006)

diagram of rear bumper Chevrolet Impala (1999-2006)

diagram of rear bumper Chevrolet Impala (1999-2006)

diagram of rear bumper Chevrolet Impala (1999-2006)

 

How to remove front and rear bumper Chevrolet Impala (2006-2012)