^It really isn't difficult, you just take the hanger from the muffler and the hanger from the body, fit them in the center H part, they go in with ease. I also used a hose clamp that was pictured above for extra security.

 

I realize this thread is old and I'm probably the last person to install this muffler... but anyhow, theres no need to put the hanger through the center of the rubber mount to raise it up. Just grab a larger sized adjustable "crescent" wrench (mine was 15") and gently bend each of the mounts down. Bend the bar down where it is welded to the muffler, preserving the angles for rubber mount. It doesn't take much force to bend them so do each side a little and check if you like it. I pulled one of the rubbers off and put a jack stand and block of wood under the muffler to brace it while I pulled it downward. Then I reinstalled it and did the opposite side. Took me 15 minutes tops with removal of the old muffler.