Giant sprites/NPC's (160x160)

[franqetesh]

What's up... Look, im doing a Dinosaurs game... In this game, there are GIANTS npcs ( the T-rex, and others giant's dinosaurs ) and you can be a giant to ( you can be a T-rex, if you evolve your dino from the correct way )... But, I dont understand how to make the size of the NPC's and sprites in 160x160... What I want, its remplace the 32x64 with 160x160.

Somebody know how to do it?