You won't find a readily visible, separate switch like you might on some older vehicles. To access and replace it, you'll likely need to work underneath the vehicle and possibly remove some parts of the linkage or even the transmission shift linkage itself depending on the specifics of your PT Cruiser's transmission type (automatic or manual).
It's strongly recommended to consult a repair manual specific to your 2001 Chrysler PT Cruiser. This will provide diagrams and detailed instructions for accessing and replacing the switch. Attempting to locate and replace it without the proper information and tools could lead to damage. If you're not comfortable with automotive repair, a professional mechanic should handle this job.
