Broken header bolts....Help!

I was planning on installing a Bassani O/R X-Pipe the other day, and one of the studs that connects the headers to the H-Pipe broke. I've had a few people that told me this would happen. I used a lot of Liquid Wrench to help the rusted bolt come loose, but it just snapped. I left the other three on and didn't mess with them. The car is just sitting there now. I was wondering if there is any way possible to cut the stud flesh with the header flange and drill out the rest of it. From there, I was going to use a stronger bolt and connect the X-Pipe. Any help or information on getting the other three bolts off and if this plan will work is appreciated. Also, will the Bassani Quiet Thunder catback and this O/R X-Pipe be too loud or will it sound good? I don't want to get pulled over left and right by the cops.

Yeah....I just don't want to get pulled over, but then again, I want the exhaust to be loud and have a good sound to it. It's okay that you couldn't give any information on the tech part. I just don't know what to do. I don't really want to buy headers, but if I have to, I will. I hope the idea works.

I've also heard heating the bolts with a torch will help. I just hope this works. Thanks for the help. Any other comments would be greatly appreciated.