Kahlid is absolutly right,
use a hole saw to get the right diamerter, or buy some dowel that fits snug, for the small holes you can just bondo, the button hole and joystick holes if you need to redrill do the wood/dowel fill and snuggy with bondo.
i like that kahlid told you to practice too... alot of people forget to say practice,
also remember to wear some latex gloves when working with bondo...