Changing a 220v outlet to a 110v

How easy/difficult is it to change an existing 220v outlet (leftover from a dryer) to a normal 110 outlet? changing the actual outlet isn't the problem. it is the breaker at the box that i don't know anything about. i know it is the only outlet on that breaker.

 

It's not hard at all. You have to change the receptacle (pigtailing the wires down to a size that can be connected to the receptacle), change the breaker down to no more than 20-amps, move the white wire to the neutral bar (if it isn't already there), and do something to plug up the hole in your panel cover (install a filler plate or a spare breaker). If the wire is aluminum, some extra complications come into play. The mechanics are easy, but the connections must be excellent, and the danger level is higher than most DIY electrical jobs (because you must open the panel).