Horn failure is common and they are extremely easy to replace. To access though, you'll need to pull the front bumper skin which will take ~ 25-30min. The horns goes b/c one is angled to ingest water and subsequently rusts/corrodes. That being said, it's not uncommon for both to go out - especially if the relay was stuck on... You can replace them w/ OEM or others have replaced w/ some aftermarket super blasters.
Below is a link on how to remove the bumper skin (for radiator cleaning which you might as well do while you're in there
). Know that if you have some short sockets w/ philips and torx bits, you can forgo putting the front up on jackstands and also forgo removing the wheels. It is helpful though to drive the front wheels up onto 2x6s for some extra clearance. Subsequently, if you don't put the front up on jackstands, you also don't have to pull the whole fender liner - just the 2 anchor pins
. You also don't need to pull the similar anchor pins (from wheel well liner) on the body panel underneath. Once you loosen the 7 bolts/screws (they changed based on MY) it will be free on the bottom.
In total, to remove the bumper skin it's:
4 pin/anchors (2 in each wheel well liner - to access hidden screw behind side marker)
4 screws (2 each behind the side marker lights - one visible one from behind)
2 screws topside below plastic panel by hood release
7 screws/bolts on the bottom (longest one in center, 2 mid-way out, 2 on each side outboard - one is tucked up in ~ 1/2")
Directions Here