UPDATE
I actually changed this to a Hella horn after WAGNER CAT left it unmounted and it filled with rainwater (thanks guys). Same procedure but also less likely to take on rainwater.
The current horn on the LMTV is pathetic, it sounds like a duck with a bad cough. I installed an airhorn by Marco Automotive called The Hurricane. It was a walk in the park to install and although the decibels only went from 118 to 120, it’s a deeper tone that better fits the disgruntled voice of Oscar.
This was a simple install. It required cutting the pigtail and attaching a few female wire connectors. I bent the bracket on the truck slightly forward and placed the horn behind it. The provided bolt just needed the current hole to be opened up to make room…. that was it.