Coleus roots so easily from cuttings that it usually is easier to simply take cuttings from the coleus plant and start new ones to bring indoors. Take stem tip cuttings 6-8 inches log with a couple of nodes (points where the leaves attach to the stem.) You can just stick them in water, and they usually will form new roots within a couple of weeks. Or you can stick them in moist potting soil, keep them covered with clear plastic (to keep the humidity high around the cuttings), and keep the soil moist until new roots form in several weeks.
After roots form, the new coleus plants can be grown as houseplants until spring, when you can transplant them back outdoors.