The voice coil on a H086 is replaceable, but you'd have to find one on ick-bay, and then you might as well use the one you buy as the replacement. The tweeter assembly is glued together and I had an H086 (A25XL) fall apart, but held together (but out of alignment, concentrically) by the magnet structure.
I do have a spare, working H087 if someone is in a pinch. I also have a complete set of H086 tweeters that work, but they are 4 ohm.
Wayner