You can use any one of the options mentioned:
9v through the Vin pin
or
USB
or
Regulated 5V into the 5V pin
In your case you just need to connect the 9volts dc into the Vin pin
You can use any one of the options mentioned:
9v through the Vin pin
or
USB
or
Regulated 5V into the 5V pin
In your case you just need to connect the 9volts dc into the Vin pin