You do that directly on the tool, changing the “Resolution” to a higher value, changes the “Size” in mm
Here are some examples of the same image changing the “Resolution” (72dpi, 500dpi, 1500dpi, 2500dpi) to get different sizes, I put some footprints as references (SOT-23, R_1206 and TO-220, the usual suspects)
Cheers
