You can update the pin on a map for a property from the Address & Map page in the property editor.
From the Overview page:
From the Property Editor:
From the Address & Map page, scroll down to the map. You'll first need to delete the existing pin by clicking the arrow icon in the toolbar on the right, then clicking the marker to delete, then clicking the trashcan:
Next, you can place a new marker in the correct location by clicking the marker icon in the toolbar on the right and then clicking the spot on the map it should be. Don't forget to click "Save":
