Hi there,
I helped a guy through this a while back (a long while back so i may be rusty!). He put a 98 (mini-facelift solid headrests) interior into a full facelift CDX.
As has been mentioned you idealy want the right age interior. That is to say pre-mini-facelift (holey headrests) is not easily interchangable with post-mini-facelift (solid headrests) due to differences in the seatbelt pre-tensioners and addition of side airbags. Worst combination is trying to put a holey headrests interior into a mini-facelift or later car as the computers will complain their side airbags have disappeared. These issues can be overcome but much better if you get an interior from the correct age car.
Of further help would be if your mate's CDX already has front heated seats and electric up down. Should be the case on a CDX (was the case with the CDX i did). This means your power and front heat switching is all in place and it's literally plug and play! You will find your front driver's seat doesn't move though, and that's because your non-elite car wont have the 20-pin rectangular plug to attach to the elite driver's seat. This contains the extensions out to the memory mirrors but also powers up the memory box under the seat which is necessary to get any movement out of it. But all you have to do to get the driver's seat working is give 12V and 0V to the appropriate pins of this connector. Unfortunately I forget which pins those are but can be found with trial and error! Other people supply 12V right under the seat rather than at the 20-pin connector but again i forget which terminals. It is easy though - trust me!
Rear seats go straight in (unless you're trying to mix estate and saloon), but to get rear heat you need more parts. You need the rear seat heat switches and the extra elite-only rear seat heat wiring loom extension. Switches just plug in under the rear air vents and you'll find the wiring for the switches there. Loom extension plugs into a square connector burried under the rear seat right on the nearside. This loom extension provides the rear seat heat relays and the plugs for the seat itself. The relays are stored in the hollow beam under the sound deadening foam under the rear seat.
Hope that helps!
Liam