I did the fix to my MR helmet. I cut into the side of the helmet from the corner of the visor almost all the way around to the back and forced the whole side of the helmet up and over. There are some pics here:
Master Replicas Fett Helmet... Revised - Brian Anderson
The paint job was ruined by this, but I was planning to convert to ROTJ anyway. I ended up molding the helmet and casting a copy to wear. I used the ears and stalk from the original on the casting.
The original was sacrificed in the process.