World Forge would be your best option to edit the map area once your items are removed. You should be able to find punts latest version at
http://worldmaker.ryandor.com but if you can not find it, reply back and I can set up a temp download link for it.
Also, you will need a couple *.dll files to run the program, so when you run the program, and get errors, read the error carefully to determine what *.dll files you need, before posting it doesnt work
The needed *.dll files should also be located on the world maker site, under 3rd party support files I believe.