Calcu said:
It's not hard to remove, you just have to remove the bumper to get it but you have to remove the bumper anyways to mount the new one anyways. It's right next to the washer bottle on the passenger side of the car, FYI.
"...just have to remove the bumper..." That's not hard?! It's a hell of a lot easier to just cut the wires and leave the stock horn where it is. There's only one, and it sure doesn't weigh much, so just leave it where it is and don't bother trying to remove it. I've also heard that in order to get to the stock horn you have to remove the right side headlight. Either way, that's way too much effort to remove the stock horn...
And yes I've installed these Fiamm horns, not only on my SRT-4, but on my motorcycle, and several other cars I've owned (SW2 and 2 LW300 Saturn wagons, Mazda truck, etc). If I remember correctly, the Freeway Blasters are rated at 125-130db, which is much louder than the stock horns on just about anything except a big rig!
To install the dual Fiamms, all you need to remove is that flat panel underneath the very front part of the car (5-6 bolts). Once that's out of the way, you'll have a clear shot at everything to mount these horns. I'd highly suggest jacking up the right front part of the car, because there's not a whole lot of room to move around under there otherwise.
As I mentioned, the horns will run about $25 for the pair, and you'll need some L-shaped brackets that fit the horn mounting posts and the bolts on the FMIC that they'll attach to, and some solderless connectors. All these things should be readily available at a local auto parts and hardware store.
Good luck!