Try using a fine-toothed comb to gently and carefully remove the strands of hair. If that doesn't work, you can try using a pair of tweezers to carefully pull out the strands. If the hair is too tangled, you may have to cut the necklace chain to free it. Make use of a jewelry plier if the hair is too close to the clasp. And be careful when attempting to open the clasp as you could damage the necklace.