1996 Pontiac Bonneville Sugar in gas tank

First of all, don't try starting it again until the mess is cleaned up. You will have to drop the fuel tank and drain and clean it out very well. The fuel filter will also need removed and replaced. Once these are completed, fill half tank with fuel and add a bottle of fuel injector cleaner into the tank as well. Run this through and you may have to replace the new fuel filter afterwards to ensure all the sugar has been pushed through the lines.