I personally just Rius Zone Masher to rename the files, then just duplicate the objects that are in my database to the new map.
If you use Rius Zone Masher just open the folder and turn offsets and all that jaz off. IF you are renaming you can let it make the wdl file, or you can just copy and rename it yourself. This takes care of all the ADTs, M2, WMOs, and any game object spawns that are in your database(aka chairs and such).