I'll tell you what I would do if this was mine, and this is only my opinion, first I would spray it with some penetrating oil like Tri-Flow or WD-40 and let it soak while you move on to the next thing, which is you drilling out the broken bolts, this takes a little time and patience and most importantly a good quality drill bit, make sure you hold the drill straight, a good bit like one of my NITRO bits will go through those bolts like butter, use a good extractor with some penetrating oil, this is where some heat works wonders, once you get the broken bolts out, use a three bolt puller, but don't just crank on it, put some tension on it and tap the balancer hub with a hammer, increase the tension while tapping it, go slow, take your time, i've removed a lot of stubborn dampener's this way, the main thing is to not **** up the end of your crank, patience,patience, put a washer in the end of the crank if needed, it will come off, a hardware store propane torch is all that's needed for the heat, that's about all I have to offer unless you can get your hands on a large, good quality claw type puller to save yourself having to extract the broken bolts, maybe someone on here can suggest an easier route, but this is the way I would have to do it , good luck, you'll get it.