Well, I finally got around to popping the lid on my cab and installing my birthday present from 9 months ago. A Sirius tuner for the Sirius ready factory Jensen stereo. The tuner is an SXV300 which was purchased through Deere and does not come with an antenna. As an interesting aside, the Sirius ID began with "LV" (Same prefix as a lot of Deere parts) and there was a "D" before the last two numbers.
Install was very easy (plug and play) and then argue with The friendly offshore Sirius customer service about the complementary 3 months subscription that the tuner came with.
There are 13 each, 13mm nuts that hold the roof on. Use a long extension for the 3 on each side of the cab (You'll need to have the doors open for access and to be able to swing the ratchet into the cab.)
You'll also need to remove both rear warning / turn signal lamps. (8mm bolt if you have rear work lights), as there is a nut under each one. You can probably get away with just removing one bolt on each lamp and swing it out of the way.
You'll also need to remove the cabin air filter housing to access the two nuts that are under there.
Once you have all the nuts removed. The roof will lift off. I did not remove the roof, as I was by myself. You WILL need two people to remove it completely. You will need to lift the roof up a bit all the way around to get the front edge to pivot up. I just placed 3 wadded up towels between the front edge of the roof and interior structure and left the roof in place.
With the mirror mount antenna, I just followed the existing AM/FM antenna wiring and secured this coax to it with tie wraps. I routed this cable through the existing grommet at the front of the cab. I was able to get it 85% reinstalled. (The grommet could have been a bit larger for two wires)
The tuner itself is very small. I wound up Ty-wrapping it to the rear radio support and securing the coiled extra antenna wire under the radio.
The coolest part was the TRAM mirror mount antenna I found on Amazon. I think it was $35.00. Very clean install and eliminated the "where am I going to secure a magnetic mount antenna?" and also "What do I do with the wire from the top of the roof in to the cab?"
Really enjoy having Sirius access now. I did not want to use my phone. I wanted a clean install and did not want a bunch of extra wires hanging about.
Sorry I did not take any pictures with the roof off. It was a bit dark in my barn.
Hope this helps someone considering the install.
Next will be upgrading the stock 5 1/4" speakers. Just as soon as I figure out how to remove the headliner without breaking anything.