I know its against all the "rules" but I "reshaped" mine.
1st removed the trim, liner and outer shell. Then using a small drill bit made a hole in the center to measure the total thickness and guage about ho much I wanted to remove. Took off maybe a 1/4" from the top and some from the sides using a semi soft abrassive wheel, cleaned it up with some 60 grit sandpaper, tried it for fit, hit the high spots and reassembled. Now I have a perfet fit. Sits right at the top of my ears and eye brows. Low enough so no more mushroom head and most importantly NO MORE PRESSURE POINTS!
