Remove Dummy Files from GDI Image

[wolfpacleader1986]

I have a USB GDROM on the way and I noticed that most of my GDI images are 1.10GB, even for games that should be way smaller like Mr. Driller and Virtua Tennis.

Since I see I don’t need the dummy files for USB GDROM, how would I go about removing them so I can save space on my USB stick?