There are several options. You might be able to fix the horns the way I did, all you need are some tools and a big can of WD40.
Remove the horns with the bracket attached. Find a way to hold them so the following works (I propped mine up with a cardboard box and some rags).
Fill the horns with WD40 and let them soak for an hour or more. Then work the WD40 out as much as possible (it won't all evaporate as it gets trapped in the horn). I have a compressor in my garage, so I was able to blow them out pretty well.
This worked very well for me.
Or, replace the horns, as has been stated.
Or .. - use your finger like everyone else. [}

]