Is it possible to convert from XM Radio to Sirius without changing the whole radio? Any internal changes?

 

If you don't have navigation the XM radio tuner is separate from the head unit, so you should only need to replace that and the antenna. The tuner is number 5 and the antenna number 7 in the image below:

 

Just saw that - but it was kind of vague. I wonder if there is a "kit" somewhere or an audio store that can do the conversion using the oem equipment without messing with the antenna or getting a separate receiver.

 

The receiver and antenna are completely different and will need to be replaced, the only alternative is to install a portable sirius receiver.

 

Why don't you just wait a little longer until they formally merge (hopefully within the next 6 months) and then you won't have to change hardware at all.

Sirius and XM have guaranteed that the new combined company will broadcast signals that can be received by both existing types of hardware.

 

Last release I saw said that if you want the combined signal you need new hardware, but you can continue using xm hardware to get xm and sirius hardware to get sirius.

 

Interesting.