I'll put this here because i searched online and didn't find any solutions. These cans are quite nice in terms of sound but the plastic hinge piece is known to break on them. Basically drilled 4 2-3mm (width) 10mm depth holes in the broken pieces and dowelled them back together with 2 nails that I cut to size. I had originally planned the 2 pieces would butt together and I would glue aswell but I think the holes were not quite matching so reached jamming point before I got that far. Seem to be holding pretty strong as is though. Sorry I didn't take any better photos but if you have a pair of these with this problem you'll get the idea easy enough. Just got to be careful to not be too forceful when putting the dowels in so to not to completely bust the plastic.