So i was following the scheduled maintenance in the manual, went to unscrew the drain bolt on the underside of the muffler and snap, the bolt head broke off. I am not very mechanically inclined but can follow instructions well, is this a important thing to do regularly? Is there another way to perform this step other than unscrew the bolt and tap on the muffler? Can I park it on a steep hill and tap the muffler to get the build up out that way. I believe this is considered a swirl type spark arrestor. Thank you for the help