Using s3dspy, Open the s3d files of the zone you wish to change (in this example we are going to use load)
1)select load.s3d from the Left hand side menu
2) find load.wld in the Right hand side menu click it make sure it is highlighted then click the rename button
3)Enter the name you want in this case load2.wld(it says one but i didnt feel like making two screenshots of the same thing sorry lol, click OK and that one is done
4) find load_obj.s3d in the Left hand side menu find load_obj.wld click it make sure it is highlighted then click the rename button and rename it load2_obj.wld
5) Rename both s3d files to load2.s3d and load2_obj.s3d and save them in your eq directory overwriting the original load2 files
and your done! hope this is helpful you can also replace textures by dragging and dropping files of the same name into the right hand side menu