Its a 250 not a 150....its a little more complicated than taking a "trim ring" off. You have to take to the whole center section of the dash out and unlike a 150 it doesnt just snap out. There is screws behind the panel that has the traction control / back up alarm switch and the the cig lighter. If you look at them there is a place to put a screw driver in and pop them out. Do that then remove the screws and then the whole thing will pop off. Then you will have access to the bolts holding the radio in.