Unless you have a huge custom tank, any leaking tank is trash. If you don't already have the space and equipment to fix it, it's cheaper and easier to buy a new one. To properly repair a tank every pane needs to be removed, layed out, and cleaned with acetone before reassembling with all new silicone. The YouTube videos of people resealing a leaking tank or replacing one pane of broken glass are more like how-to videos on flooding your living room. If you do decide to repair your tank please make sure it's done properly.
It's really hard to tell from your pictures but it looks like the metal frame may be welded, if it is, the only way to get it apart would be to grind the welds off. It would be very hard to put it back together and would require the work of a very experienced welder so the glass isn't overheated