Haven't owned an ATV for 14 years and just purchased a new 300EX yesterday after extensive study. I'm already having flashbacks of my younger days. HOW DO I GET THE BAFFLE OUT OF THE MUFFLER???? Not ready for the high dollar aftermarket exhaust yet. It seems like they must have used loc-tite on the screws. I've already ground the spot welds off and broke my Snap-on screwdriver attempting to remove the screws. Please Help!

 

Don't have any Honda's, don't know the construction of the pipe really, but I assume you've tried heating them. Try using a "EZ-out" screw extractor. Can get 'em at any hardware store and in different sizes. You may need a "tap - handle" also. Vise-grips will work on the extractor but is aggravating.
Drill 'em out completely maybe.
Good luck.