All that was left was to mount it on the bike. It simply clips to the front of the basket. I found it helpful to stabilize it by running the elastic band as seen in the picture below. First attach the band to the top two posts (as if you were restraining a bag or something), then clamp the horn (clamp between band and basket), and then just detach the band from the posts and hook it around the front of the clamp.
All that was left was to strap the button next to the bell