If you haven't divided your daylilies in a while, consider it this year. Fall is the most common division window, even as they can also be divided in early spring.

Start by cutting back the tops to about half of original height. This should make plants easier to handle.

The root system is tough to divide, and made harder if it has been a long time since the last division. Use a spade to lift the entire clump out of the ground. Use a garden hose to wash the soil from the clump, and then roll the clump back and forth until the individual divisions separate. 

Space divisions 24 to 30 inches apart, and set each at its original depth. Flowering will be reduced the first year, but each division should return to normal by the second year.