Nobody knows really, this is the reason so much hell was raised over Playmore having to reprogram the SSVS carts. The best way is to stick a screw driver in the side cracks and gently try to loosen the plastic tabs that hold the case together.
With all the mods done to these to make conversions ext someones gota know hehe.
I figured it out. Thankfully 3 out of the 4 empty carts i have didnt have the bottoms on so i could see where the inner tabs were.. Used my thumb nail to lift open 3 tabs on each side and pop! It came apart.
Lookin to make me a Phantom Shell.. If i do it right i'll have 4 total and see off the other 3.. Thats if i dont make a hack job outa it.