what brand silencer ? The stock silencer has no packing in it, most if not all ? aftermarket silencers have packing in them and would need to be changed at a certin amount of hours? <<< i cant remember... Anyhowe, some aftermarket silencers use screws, screwsand rivets or just rivet they can either be screwed out or the rivet would need to be drilled out and use either new rivets if you have a rivet gun or if not than you can use machine screws.. It is not hard to do and most if not all exhaust silencer packings comes with instructions..