Raise the front end of the car on ramps or jack stands.
Remove the plastic shield from under the bumper. It's held by a dozen
screws with a 8 mm hex head.
Loosen the clamp that attaches the inlet pipe to the airbox. If the car is
old enough and seen road salt, chances are the clamp is rusted shut and
you need to cut it.
Pull two plastic screws in the upper corners of the grille and lift the
grille out of the way. Remove the screw holding the pipe to the bracket
(10 mm socket).
Slide the pipe off the airbox and remove it from the car.
Old vs new
You can see how much thicker the new Aero pipe is compared to the old
Fit a new pipe on, secure the upper screw and restore the grille.
Slide the pipe onto the airbox and tighten it with a new stainless 3"
hose clamp. Fit the shield and lower the car to the ground.