It's very possible and safe, if you are careful and get a good bite usibng a plastic scraper to break the seal, then you can use a car jack to pop off the corners.
You use a piece of wood or the jack top to push the top lip off.
Add a piece of cardboard to prevent glass scratches, on the side.
Place base of the car jack on the bottom lip so you have leverage against the top.
After it's off, now you'll need to remove all that silicone.
Razor blades work well. You will also need to remove and sand those shape glass edges.
You can buy 20 gal ADA tanks from Aqua Forest in SF.
They ship and are fairly reasonable.
exclusive cheap semi soft enriched clay Barr Substrates for subscribers only! Molasses added to encourage growth of bacteria and mychorrhizal fungi. Cost relative to "MPV Turface", doing an ADA soil vs this product presently. Various grain sizes also(Dark black brown color) appears very much like ADA aqua soil except 10X cheaper (and much cheaper than Onyx/Flourite etc). Various nutrient content options also. Available late Oct.