2005 LS 6 disc head unit (Sirius ready)

[05LSLuxury]

I purchased an 05 LS Luxury 2 weeks ago and have a question regarding the head unit. The Luxury model, as most of you know, comes with the single disc/tape deck unit, not the 6 disc unit. I am looking to replace the current unit with the Sirius ready 6 disc unit. Is it possible to swap the single disc/tape deck with the 6 disc unit? I am not looking to replace any other components other than the head unit and have been told that this is not possible.
I realize that I would need a new dash trim plate to surround the new unit.
Any help would be appreciated!

Thanks,
Chad

 

[Pepsi2185]

As far as changing the head unit on the LS's i have not came across an amplifier yet, but i also have not worked on anyting past 04, and no alpine systems yet. But the regular sound system is just a glorified ford deck with the old continental 6x9 subs.