Personally I'd use the grinder to get the majority of it off. Be careful with it! Then get a coarse file and knock it down, then a finer file, etc.

The other option, if they really ARE brazed on (and not welded) is to get a torch and melt the brass and blow it off with compressed air. The thing should come right off at that point. Then, when you have it off, sand it down or file if necessary to remove any high spots.

Others probably have more experience but that is how I'd go about it