How to rig this model, including his hat?

So, I have been working with this model for a while now, as I have a very small team of close friends who will be helping me with my game. This is a non-profit HD remake of Zelda: Majora's Mask.

I was wondering if it would be possible for me to rig this Child Link model in Unity, including his hat. If so, how?

I was also wondering how I would be able to animate him so that when he walks, his tunic moves with his legs...

Any help would be greatly appreciated.

Thanks! /PwnzLPs