Ok kool you tried the easyout. He is a little trick with easyouts. As you apply pressure to the broken bolt (steady pressure) tap the end of the easyout with a hammer. A good penetrating oil is your friend here.
You may need to apply heat to the surrounding material if possible. You want the surrounding material to expand thus allowing the bolt to turn.
As you said you may need to drill it out. In that case there are several options. You may get away with being able to retap it. Also you can use Helicoil
also there are Keensert
. There are many other options. Those are two that I have used succesfully in the past to repair threads.