Just be careful to grab just the headband when stretching it, not the plastic ends of the headband as these are a bit more delicate than most of the rest. The headband is designed to withstand 10+ flat-bends without deformation, so you can go a bit beyond that to actually loosen it. You'll find videos of that online, even by Val himself.
I might add that V-Moda sells deeper XL-pads as an accessory as well in case pad depth is a problem (did not try them out as the standard pads fit my ears quite fine).
Enjoy your new headphone -- Deep House is a nice genre to listen to on the M-100.