How do I override the gx470 navigation system so I can make changes to it while driving

You don do nuthin wen drivin cept drive. No messin wit the gx or fone or cd jus drive. and thats just the way it is

depends on the changes you want to make but the setup menu is a good place to start

For safety reasons, all navigation systems are disabled when the vehicle is out of park. You can not override it.

reading the manual might be a good idea

It is a safety feature installed in all Toyota/Lexus navigation systems. There is no way to override it. Toyota/Lexus does not want you to be distracted while your driving.

l google it buit no look it a safty featue.
ino over ride ;-(

You can not. Stop driving, put it in park, and change then. It is a factory system with no override. If you want one that you can override, try looking into aftermarket nav systems.