Holy F that looks lit, could you describe the exact process that you did to fit these? i find hard to believe that the oval shape of the HM5 looks so round on yours, also, how would you describe the confort? better, worse?
Coming from HD600, I can't use anything else but velour earpads, so the HM5 velour pads was a great upgrade in terms of comfort.
What I did was to use a scissor to cut off the pleather lip (what you usually use to fit it to other headphones, so this is not something you can do if you use the pads on other headphones), then I just started to stretch it from the inside in all directions, trying to make them as round as possible (you have to start out lightly and then increase force as you don't want to rip them).
Then after a while of stretching, when I saw that it was getting a lot bigger than before (just compare to the backside of the headphones to see if it's covering about 80-90% of the grill), I placed one corner first on the excisting adhesive (from when you pull off the pleather pads) and just shaped it like a circle, one step at a time, trying to apply enough pressure so that it would stick.
And you're done