remove 1mm?

Hi there,

I have a part/jig for a component to sit in. I took the outline of the part and used that to extrude, however I need this to be a prox 1mm bigger to the component sits in side it. using the scale function returns ofset reults due to the shape of the cut-out.

Is there a away to just trim 1mm from the circumstance?

I've attached the part and component,

The component(fan) sits inside the part(jig) but needs a 1mm gap all round

SolidworksParts And Features