I have no experience with glass!! remember this before continuing...
are yu cutting the panels into different sizes or sperating the seams and reassembling the same tank later?
if you are disassembling at the seam and it is siliconed, I wouold try a heat gun on the seams. I do this on automotive sealing surfaces that are sealed. Like a oil pan or differential that has no gasket, just silicone sealer. Heat it up for a bit then use a little pressure at the seam with your hand. Like i said before, I have NEVER done this on glass but I don't know why this silicone wouldn't act the same, should work at lower temp then automotive silicone.
and I assume you are going to frame the tank to keep the other panels in place as you rmove others.
just a thought...