It is written fully in Russian, Im not sure if you can translate it all well. I can try to do it later if I have some spare time. But anyway, you can find it here - http://www.doctorhead.ru/forum/viewtopic.php?f=124&t=15330
Basically in two word. You must take driver completely apart, make all magnets even (grind them, or order new ones) and place it as even as possible. Then make all geometry perfect, and remove (grind) all unnecessary driver housing parts that can additionally interfere the sound waves. Then place it in open housing and make new ear cushions from leather.
Not an easy task for sure. Possibly more complicated than Thunderpants mod. But results must be even better.
TDS-15 alternative variations. Green - graph to match HE-5
He also making LCD-2-ish mods, but I did not spot a graphs.
Thank's for sharing the links! This makes me very curious about how the TDS-15 will sound with new ear pads.