Call kyle @ Goldwing. He'll send everything you need to swap and it'll be less-expensive than a dealership/mechanic.
I think I remember on the '99 that the alternative is to use an older ECU, as the rest of the t5 cars didn't have immobilizers. It's nothing I've ever had to deal with, though, so I could be making it up.
2008 9-5 Aero-1995 900T 'vert