It's a piece of cake.
It plugs into a CD changer port (for want of a better word) on the back of the radio, meaning an OE CD changer could plug in there otherwise.
I've never seen a Crossfire with a CD changer but that's beside the point, I have the Infinity w/ navigator and it plugs right in, just like an OE plug. The radio is really made by Becker by the way, I don't understand the Infinity branding.
It will take forever to get to you if you get it from eBay, mine took 6 months.