I just dremeled it....very slowly with a small bit and carefully enlarging and rounding it out until things fit.
it was time consuming.
I sure wish I had a drill press.
The sound out of these things rock. I'd describe it as clean and transparent...faithfully reproducing the source.
I have the Fiio E5, don't laugh, and the mini makes it sound bad.
still haven't made any decisions on labelling and as Juaquin mentioned, I'm leaning towards minimalism for now.