ORIGINAL: speedster 1919
Loosen muffler clamp bolt and nut. If your in a hurry take a flat blade screwdriver and spread the muffler in between the slit . Not in hurry spray a little penitrating oil and the next day heat flange with heat gun or torch and it will twist off . Use gloves...........
I read somewhere that problem with the ST manifold joint is caused by the metal of the two parts fusing together. Whether or not this true, I know they can be a SOB to separate.
Anyway, to prevent it happening again, you need to use some kind of grease (I use copper grease) in the joint. And if either of the parts has become nicked, take some time with very fine sandpaper to smooth the metal, as it only takes a tiny bump to bring everything to a halt.
Matthew