Ok, here is a little guide on how to stretch your headphones without snapping them and getting a perfect bend while relieving like 90% of the vice grip clamp.
1. Find a box that is slightly larger than your heads width (1/2" max). Don't use pillows or soft objects, as it can create a lopsided bend.
2. Adjust the height adjustments to fit your head.
3. Place the adjusted headphones on the box like you would do normally stretching your headphones.
(This is the normal way, but the metal frame and plastic are way too stiff/strong and have crazy memory and eventually return to shape after a few hours. I did this for a few weeks and they would always return to really bad clamping. This is what led me to start bending them by hand and snapped my first pair. Bending by hand will also give you an uneven bend.)
4. Now get a hair dryer and put it on the highest heat setting and start heating up the top portion of the headband. If you use a heatgun, becareful with the heat settings. Don't go below the plastic frame where the L/R labels are and don't do the underside where the padding is because I'm assuming those are glued on. Heat the top metal insert until it's hot to the touch and then stop heating it. Try not to direct the heat towards the drivers, or even cover them with a towel.
5. The heat will make the aluminum/metal lose a good amount of it's memory from bending, but it's still going to slightly bend back, this is why we want a box slightly larger than your head.
6. Let them cool off stretched out over the box for 30 minutes and then try them out. They should be a lot more comfortable now. If not, do it one or two more times, or adjust the box size to your preference of clamp.
After doing this, I can now wear them all day with 0 headache or pain. No more enduring months of pain breaking in your headphones!
This also helps the sound in a good way, IMO, as it stops shoving the drivers down your ear canals. Makes them sound more natural and the bass isn't as boomy.