I ordered "Yale AYRD200SCKA26 - Keyed Alike Schlage Style Barrel for 619 Finish Yale Locks" from asihome. They were $14 per lock and very easy to replace. Remove a plastic retainer on the outside escutcheon (2 screws), and remove a single screw holding in the cylinder. Pop in the new cylinder and reverse. Very easy and works very well. Be aware that you'll have Schlage keys with YALE heads, and this will cause confusion at lowes when you try to get other locks to match your new keys. :-) Be sure to order the KEYED ALIKE option and order all of them at once, otherwise you'll have to get them rekeyed.