Soak them well with something (as above) like a penetrating oil and let it sit overnight if you have to. The first time off is a real bear so don't get discouraged. After that, keep them well lubed to facilitate future ease of removal.
You just have to lift and swing at the same time, rock it back and forth. If you have it partly closed it helps sometimes.
06 Rubi with some sort of double ended, chrome knobbed, cross threaded, infinitely adjustable, frequently breakable, worn out flammywhammers zip tied onto it.
It used to be a jeep thing... til that sh!t broke!