Depending on the year of manufacture, the attachment points may differ.
Front bumper
-open the hood.
-take out the caps and remove the trim over the grille.
-under the trim take out the five caps (inserted from top to bottom).
-at the bottom of the bumper, Unscrew the screws (spun up).
-turn the wheels to the side.
-wheel arches take out the caps and release the fender liner (front).
-unscrew one screw on each side that attach the corners of the bumper to the wings.
-with an assistant, pull the bumper forward (look for the wires).
-disconnect electrical connectors (if any).
Rear bumper
-open the trunk lid.
-in the opening of the trunk take out two plugs and Unscrew the screws under them.
-at the bottom of the bumper, take out the caps and Unscrew the screws (twisted and inserted from the bottom up).
-in the wheel arches, we release the fender liner (rear).
-unscrew one screw on each side (spun up) that attach the corners of the bumper to the wings.
-we release the latch in the wings (pull the corners of the bumper towards you).
-with an assistant, pull the bumper back (look for the wires).
-disconnect electrical connectors (if any).
How to remove the front and rear bumper Toyota Avalon (2000-2004)
How to remove the front and rear bumper Toyota Avalon (2005-2012)
How to remove the front and rear bumper Toyota Avalon (2019+)