Halfway through correcting it now. Chipped it out with a screwdriver, cleaned it with a Dremel wire wheel and rust converter (mostly phosphoric acid gel stuff from Rustoleum), and sealed it with primer. Next up is Bondo filler putty, sand, then reprime and paint.
![Image](https://hosting.photobucket.com/images/e185/txnavy/06DA3ECF-EE7F-441A-A5C6-C5A03114CB3A.jpeg?width=960&height=720&fit=bounds)
One comment, Nissan HSLA steel is pretty magic, there was water inside the rust bubble when I chipped it out but plenty of good metal left underneath. It was nowhere near working its way into the roof liner, which is what I was worried about.
When I'm done, I'll take photos that explain how to get the roof rack off. It's a lot easier than you think. It The rail pivots on the center mount to an angle...slide back, then it pops right off.