How do you remove seized torque plate bolts on a 2000 Toyota Solara?

I'm wondering if you mean "flex" plate? A "torque plate" is something that's used during engine assembly and I can't imagine bolts seizing for a temporary installation. A "flex" plate is the disk at the rear of the engine in an automatic transmission car (replacing the flywheel of a manual transmission vehicle).

If it's actually flexplate (or any other bolts) that are seized you have a couple of options. First I'd use a liberal amount of penetrating oil on each bolt. Let sit 24 hours. The oil will work its way through rust. If you still can't remove the bolts with an ordinary wrench, try an impact wrench. Your next option is heat. Try heating the bolts with a propane torch then hit them with the impact wrench.

Cheers