The way I did it, was I put it upside down on the CG machine, set the machine to the CG of choice, mine was 6", I already had the battery removed and I set it on the rear portion of the fuse and just moved it where it needed to be for a CG of 6" and marked the fuse. Then I just cut a hatch, added some scraps to snugly hold the battery in the fuse, added a tongue to my hatch, created some mounts to screw the hatch too, and screwed it down. If you use a sharp exacto and make some clean cuts, you have to look to see that it's even there.