I had one of these for my Nokia CK-7W when I bought the car, and was removed instantly. iirc there is one screw behind the stereo that holds the bracket in and it slides between the black plastic trim and the aluminium bit. Sadly it has damaged the plastic ever so slightly but not too bad.
The instructions could be clearer! What they should say is:-
1) Lever up the whole aluminium surround from around the gear leaver by prising it up at the back. Because the aluminium is mounted onto thick plastic you can do this without any damage.
2) Disconnect the wiring from the hazard switch etc and undo the gator and the whole panel comes off.
3) Undo the two screws at the bottom of the main aluminium dash panel.
4) Remove the radio.
5) Undo the two screws that hold the radio cage in.
6) Carefully lever out the lower left edge of the main aluminium dash panel and slide in the phone bracket to meet up with the radio cage screw hole. Now this bit is not easy but with some care it can be done.
7) Reassemble, and the hardest part here was getting the gear lever surround back in. The trick was to really push it forwards before bedding it down.
Still sounds easy but it takes a lot of pushing and shoving. The result is very secure and there is no damage. You could complain that there now is a bit of a gap between the left edge of the aluminium dash and the surround but this seems to be closing up as the surround squashes down. To be honest you probably would not notice if I had not mentioned it.