I replaced 3 out of 4 rotors on my 05 Cabriolet the last time I did my brakes. The passenger front bolt holding the rotor in place would not come out. Had three different people try to get it out, six hardened star bits and numerous bleeding knuckles later I put the new pads on and left it until now!
What are my options? New hub?

 

Liberal use of PB blaster or similar, let sit for a day or so. You say 'six hardened star bits' - do you mean you broke them? Stripped it?
As an alternative, just drill it out. The screw really just holds the rotor on while the wheel is off. Your experience is not unusual.

 

the flat head screw goes through to the back and gets smeared by a rock or whatever,then it won't thread out. Drill it out and get a new one.

 

Yes broke them! I broke 2, the tire store broke 2 and way motor works broke 2. I'll just drill it out if more PB and heat don't work.

 

Drill out is the quickest way to get it out, or what I have done in the past for a bolt holding a two piece rotor assembly was to weld a hardened bolt and backed it out that way, but that was when drilling wasnt an option.

 

Have you tried an impact driver?

 

or an Easy-Out (EZ-Out?)?

 

Easy outs are a tough bet when dealing with metal on metal. In my personal experience i have never had any success with one unless its relted to home repair. Heat and an impact driver should do the deed.


the manual is what i prefer to use

http://en.wikipedia.org/wiki/Impact_driver