Retro-fit Xenon Angel Eyes !!!

[jpohl402]

Greetings,
Saw today an 01 X5 with Model Year 2011+ (i.e. 5-series style) - Xenon Angel Eye circular headlight rings/daytime running lights. Of course they look killer & updated !!
So, being the fact that thing car was an 01, how difficult/what steps are necessary to retrofit this into an 04 X5? Do you need the entire headlight assembly? Or is there a kit that you can buy to wire into the Headlight Rings (much like aftermarket HID kits??)

Thanks in advance !!