Several people have drilled out the rivets around the muffler to start gutting the inside of the exhaust... it's usually a lot of work if you don't have a 'drill press'
But I have no clue how to open up and gut your current exhaust from that pic, would need a side/top/bottom view... rarely they give you some kind of hex/Allen wrench style bolt that doesn't need drilling out, doubt it would be on any china bike tho
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