I didn't need the muffler mounts with the HMF, so I removed them.
First, I cut the mount ring off with a hack saw.
I use some spray auto paint stripper. Any will work, I had this already.
Don't forget to wear gloves.
I then smoothed and shaped the end on my bench grinder.
I finished the smoothing and contouring with some fine emery cloth.
I mirror polished it with some red rouge and Blue Magic Metal Polish.
They came out great and go well with my HMF exhaust.