Dealing with rust

I figure the people on this board would have some answers so here goes. Took my van down to get the front window replaced and they found some rust around the frame and ledge under the rubber. Only has one really bad spat about 2" wide that actually rusted through and I know I have to cut it out and replace. It's the rest of it that I have a question about. Should I grind it away and then try some of that coating that turns rust to carbon? What is the best tool to use to remove the rust before painting, and do certain rust treatments work better than others? Any help is greatly apprecaited.

 

For a permanat fix, you need to cut it all out, then replace with fresh metal. If you don't have the means to do that, then wire wheel it away as much as you can, use one of the commercially available rust converters, then paint over it.

Don't just wheel it off and bondo over it. Remember, if you cut it out, go far enough to get to good/clean metal...you mention a 2 inch section, so probably need to take out 5-6 inches to have all clean, good material to work with.