The amplifier is located underneath the passenger side footwell.
Start by removing the floor matt and pulling the carpet up from the footwell.
Step2
Remove the foam board and you will see a metal plate to which the amp is attached upside down.
Step3
Use the socket wrench to remove 4 nuts that hold the plate. Pull out the board.
Step4
Replace the amp with a new one.
Tips & Warnings
The stock amp is running at 1 Ohm and most aftermarket amps run at 4 Ohm. You may want to consider upgrading the speakers as well so the aftermarket amp can run efficiently.