Originally Posted by Gene T
I agree. Removing broken bolts is difficult in larger sizes, but with anything less than 3/8" it's downright ugly. I have seen the tig-weld-a-nut-to-it approach work, again with larger sizes. When corroded, the difficulty goes way up and the chances of success go way down.
There are some good extractors on the market - they are NOT "easy outs". The Alden "Drill Out" works well: http://www.drill-out.com/how1.html
You'll want to heat the broken bolt red hot with a torch. Search Youtube for video demos. Hell, it's worth a try.
Personally, I would just shop eBay for a good used block, or another putt-putt.