Put new diaper under the old one, open old diaper , lift both legs and clean the area with wet wipes, put some desitin on the skin, now slowly slide and pull out the old diaper from the top that way you have the new diaper in its place. Use the velcro on the new diaper to attach. Throw the old diaper on diaper genie. Remember to change it every 2 to 3 hours or when they wet or soil the diaper.