Greetings,
Same Passlock problems as everyone else... blah, blah, blah... sad but that's GM. Here are few hints from the resolution on my 98,000 mile 2001 Olds Alero. I didn't have to take the radio or heater controls out... all I had to do was take out the two 7MM bolts that hold in the frame/bezel around the instrument cluster (Speedometer, Tack, Etc). Once the bolts are out put the Tilt wheel in the lowest setting and pull the frame straight towards you - the two clips on the bottom will release. Now unplug the Trip Reset button and set the bezel aside... you have all the room in the world to work on that magical yellow wire because it's sitting right there in front of you with enough slack to cut and add the toggle switch wires.
While I had the instrument cluster bezel out I ran the toggle switch wires through the openning and over to the fuse box by the drivers door and installed the switch there. In a Grand Am we owned, the switch was right under the dash and occasionally got hit accidentally... nothing but trouble. With the switch in the fuse box there's no way to accidentally hit it.
Using this method will take you just a few minutes to complete and with no risk of damage to the radio, radio bezel or console plus you'll be seated comfortable in the driver's seat rather than like a contortionist in the radio opening.
By the way... the car does NOT have to be running to do this... just remember to swtich the switch to the "on" or "closed" mode when starting the car the first time. Once it's running, throw the switch to the "off" or "open" mode and the "security" light will come on. Repeat the process if you ever have to change the car's battery.