Gently, gently. Radiator hoses usually get stuck to the nozzles. You can sometimes twist them and they will break free. Don't use too much force. Alternately, you can take a narrow putty knife (or something like that, an old butter knife, for example) and bend it 90 degrees. Use this to slip between the nose and the nozzle and gently slip it around to break the hose free.
Whatever you do don't rush and don't use anything more than gentle effort.