You mean a aftermarket radio? Need nothing. The factory end of the factory sat radio antenna; just unplug it from the box, undo the harness clip on the end of it so you just have the circular peace of the antenna and plug into new radio. Works as is.
The box behind the radio is the tuner and you do not need anything plugged into the new radio.
You will have to go online or call to change the radio. I did mine right on my mobile after I hooked it up. After read the directions for you aftermarket radio to find where you Radio ID number is. Once you have that, just plunk it online and within few minutes new radio shall work