I could use some tips to get an older FMF powercore muffler apart for repacking. I've taken the bolts out of the muffler near the head pipe, but I cannot figure out where to tap on the muffler to get the it apart. The videos that I've watched shows holding the muffler in a vise and using the rear mounting bracket as the surface to tap with a hammer to get it apart. My muffler is the older style that does not have an attached rear mounting bracket. It has the clamp style that is a separate part, to I don't really have a good surface to use to tap the muffler apart. Should I be drilling the rivets out of the back of the muffler and pull the core out from that end? Or should I try using a flat screw driver or a chisel on the lip of the muffler near the head pipe?