So i'm trying to take off the muffler of my bike because i managed to stripped the threads on the oil pan after i changed the oil. I plan on rethreading the pan but to get it off i need to take of the muffler and possibly the exhaust. But they are STUCK. i tried grinding down what i thought was rust but looking at it now i'm curious if it's just welded. I'm an experience mechanic but i do enjoy tinkering around. I took the mufflers off my old bike but these once seem to be stuck. any suggestions? i will send pics but i'm new here and need to have more posts before i can. thanks. any info or ideas are great.