I have nikon d300 and the front dial is damage. How can assign other button to change the aperture? And also it has snapbridge or bluetooth? I don't have computer or laptop to transfer photos.
There is nothing you can do about the front dial other than repairing it. Such cameras are designed to be operated that way and there are no redundant controls. Even though you can swap the dials, some features require both or constantly swapping would be impractical.
The D300 is rather old and has no Bluetooth which implies no SnapBridge support since that is just an app that uses Bluetooth.
The best way to transfer photos is to use a card reader. Those are available for under $10. They are faster than using the camera and do not use up its battery either.
You can swap the two dials so the rear controls the aperture. It is a custom setting. Not very convenient if you have to switch it back and forth but it might help you in the short term.