I picked up one of these from Ebay about a year ago and never actually installed it (partly because of laziness, mostly because I'm confused )

Sadly enough, I searched for a how-to for a horn installation....can't find anything on the org about installing them so I was wondering if someone could give me a brief walkthrough.

I was thinking this was gonna be a plug and play thing, but the horn comes with a relay that I have no clue what to do with.