Mouse,
The AC in both my TC's were factory installed. If you are a reasonably accomplished DIYer I would think you could complete the install. The duct work is under the dash/console and does not appear to require any major modicfications. I might suggest you order the service & repair manual, along with the parts book for your specific TC, or at least stop by the dealer and look at the diagrams and review the parts list for the AC kit first. The manuals are not that expensive, at least not expensive compared to my Case Loader which was well over $200.00 for just the service & repair manual.