Just recently the driver and passenger side door locks are not working. On the driver side the lock will not unlock when I press it but it will lock. The passenger side the lock will unlock but it wont lock. Also when I try to lock the passenger side door with the key from the outside it wont go down but the other doors lock will go down except that side. Can someone help me find out where should I take it to fix this and like how much will it cost? Is this a really hard thing to fix?