I agree with Tjohn trim the dead part off, put in a glass of water and let nature take over. Its best if you can to let kitchen water sit for a few days before using, maybe use bottled water 1st. Also you should change water every few days to replenish the oxygen in the water. I work in the garden center of Lowes [know very little about plants], I find pothos cuttings all the time that have fallen off, have my dresser top covered with bottles of cuttings to try and save. I figure what the heck, if they root then awesome, if they don't then I tried, they would wind up in trash can anyways.