So I have the wooden cups for the Hifiman HE-series for sale. Since I have two left hands (and that's a compliment) I don't dare to perform this mod. They are 100% new. The cups are handmade by Head-Fi member Munkynutz and cost me 150$. I'm taking 100 euro excluding PP and shipping cost. It's a sweet deal for the quality you are getting. It will make your Hifiman a whole lot more special.
I have two cups and two cimbals (or whatever they are called :P). See the picture for the color. They have the holes and pretty much just have to be installed!