Not sure about the state requirements, but changing locks is always legal. However, the pendulum can swing both ways. You could, in theory, call a locksmith tomorrow and have him change all the locks to something else entirely. If your name is on the deed, and there is no paperwork, either one of you can change the locks.
With that being said, if you need to go onto the property for some reason, call your local law enforcement and explain what you need to do. Have your paperwork with proof of ownership and ask is they can do a domestic standby while you retrieve your items. Depending on your local law enforcement, many will do this because it requires less paperwork than the false allegations that come from someone going onto disputed property without a domestic standby.