Rust - My Nemesis
 

When I bought this car I knew it had one rust spot and I don't know if the previous owner did the bad job to hide it or what and I'm looking for suggestions on patching it up.

I've never done rust repairs besides a few Bondo jobs in the past but that was more of rust spots on the bottom edges of vehicles. Also the bubbling of the paint also makes me think that the previous owner had no idea what he was doing to fix the rust. I think he just painted over it and called it good.

http://imgur.com/a/tOOxV

If link doesn't work Mini Rust - Rear tailight - Album on Imgur

How would I go about fixing this rust?

Thanks much for any assistance!