Bi-Xenon in prefacelift lights?

Has anyone retrofitted the E55 projectors in a prefacelift housing? I've read varying accounts of this from "no problem" to "PITA".

Can this be done without hacking up the light housing and just modifying the projector?

And do I need different bulb holder pieces or can I use the metal retaining ring from my OEM ones?

Anything else to be ready for?

Thanks

Bi-Xenon in prefacelift lights?