anyone know how to get rid of this rotor rust ?

Check this pic of my rotor... caliper pad isn't touching about an inch of my rotor. that's why the rust is on it all the time.

 

a wire wheel on a dremel will do it. Painting it with high-temperature paint is the only way to keep the rust off permanently. Most people don't bother.

 

I'm going to rid mine of rust when I get around to it. I'll be using wire wheels (a 4" one and rotary wire brush) chucked in the electric drill. I'll remove the caliper and its bracket (4 bolts I'll bet) and get both of them out of the way. Then I'll brush off the rust where it shows on yours, the "hat" (the bit in the bottom right of your rotor) and the ventilated outer edge. Then I'll apply a coat of silver Tremclad followed by a couple of coats of hi-temp silver paint. I'll remove the rotors (two big Phillips screws hold it on) and do the back side too.

You can get a bit of paint on the swept area of the pads as it will get worn off in the first few revolutions. Don't go nuts and paint the whole thing though.

An "impact driver" is the best tool to remove those phillips screws.

I'll be painting my calipers and brackets too while they're off. Calipers black, brackets silver. The Brembo calipers on the front of my TL-S are already black.