I am modifying a wordpress website which has google maps as a plugin (although it's not on the plugin list). On the map which comes up when visitors open the contact page there is a red marker which indicates the location of the business. But the location has changed and I don't know how to move the marker. I have changed the address in the dialog box for the map - it was found by the system, I saved it, then updated it. But the marker doesn't move. How can I fix this?