I have 2 broken bolts inside my rotor.. how do I go about removing them ?

 

which rotor - ie the brake disk? maybe posting up a picture would help? Generally speaking if there's enough of the stud to grab onto, you may be able to PB Blaster it and then grab with heavy duty vise grips. Otherwise you may need to drill it out and retap the thread. Tough to say what's best without seeing which bolts broke.

 

I have used the welder method many times, With the heat generated from the welder it often makes the removal pretty easy. Sometimes the bolt will still fight you but if you watch this video you will see the guy goes back and forth when removing the broken bolt, that helps to keep it from binding and getting stuck again.