I need an existing 3D figure hollowed

Good morning,

This is a non-design job, just a quick edit for a quick $20. I have a cat pendant that I need hollowed out to reduce cost of printing. I am going through shapeways so it NEEDS to be compliant with their printing rules. I have the original file (which needs to quickly be resized to be 1.5" tall) and then I need the body of the cat to be hollowed out appropriately to meet shapeways requirements of wall thickness for stainless steel, so that I can cut down on the cost of each print.

If you think you can help me out please feel free to contact!