how to delete walls from Decor8

Is there a way to delete walls from Decor8 program? I looked in the walls folder under the Decor8 folder but it does not show all of the walls that are showing when the program is active.   I have added a couple of walls to the program but can not delete them, if I no longer wish to use them.  Are the walls  located in another folder? I'm using Windows 8 Pro.  Have no problems with the program at all. It works fine. I also have Start8 and Modern Mix. They all work great.