From Longman Dictionary of Contemporary Englishunhookun‧hook /ʌnˈhʊk/ verb [transitive] to unfasten or remove something from a hook→ See Verb table
Examples from the Corpus
unhook• Currently such research is obliged to have only one aim - unhooking existing addicts.• I stood on the low wall and tried to unhook the basket.• I heard footsteps and then Sonya opened the door without unhooking the chain, just enough to check me out.• She unhooked the chair, dusted it off and carried it back to the front lawn.• I begin to unhook the keys.• He unhooked the tag from his jacket and held it out to Jen.• Can you unhook this necklace for me? 