Broke my water pump bolt. Now what? (Update - broken bolt is out)

Easy-outs can cause worse problems if they snap off to leave hardened steel in the bolt which can't be drilled out. I've only had success with them when I drilled a perfectly centered hole in the bolt to almost the thread diameter so could use a big Easy-out. At that point, you can often fold the remaining bolt shell inward to peel it out, or cut the remnants out with a tap. Looks like enough threads to grab well with visegrips with sharp teeth. Work it back and forth. Once the bolt budges, you are almost home, just need to keep flushing solvent and working it back and forth to flush rust particles out of the thread gaps. They jam in there to keep the threads from sliding. I agree with tapping the end of the bolt with a hammer after solvent has gotten deep in the threads. That helps break up the rust by hydro-shock and flush it out. Similarly the expansion and contraction from heating helps break the rust bond.