Don't get the black projector housings because they are crappy!
If you have the $$$ for getting good HID (bi-xenon) projectors, then do it right the first time and you would be much happier!
Taking the lense and the housing apart is fairly simple as many have done it for various vehicles. You can search the Net and it'll tell you to use the oven or heating gun to do it. You put them back together the same way.
Anyway, good luck!!
I did work my way through that big thread about those projector housings but what is it exactly that is bad? I currently run the standard(aus) dual semi-sealed beams and they're crappy, the beam is good but the light output(especially low beam) leaves much to be desired.
I don't really have the funds nor the interest to do a HID projector project at the moment, plus its quite hard to do it legally in Australia as far as i'm aware.