I think a few people have done this and there are probably a different ways to do it. What I had done (before swapping the pipes all together) was simply shove a 22 mm drill bit up the end of each pipe and drilled out those annoying plates. I started with some smaller ones but that may not be necessary. The sound was improved a lot over stock. You could hear the bike and I didn't feel like I was riding a scooter any more. The nice thing about doing this is that it doesn't cost anything, you don't need to remove anything from the bike and it only takes a couple minutes. Good luck!