This requires basic modding/mapping skills and several programs.
Kaelic's MEG extractor
First, this is the FoC version, so EAW might or might not be alike.
The line containing the parameter DEMO_ATTRACT_KAMINO.ted (should be in the top 20 lines) can either be used as reference or changed to whichever map you want. To edit this map, keep reading.
Extract MAPS.meg with the Meg extractor. Open (With the .ted editor) DEMO_ATTRACT_KAMINO.ted.
It should be under FoC\Data\Art\MAPS
Edit the map as you wish, and save.
For a mod, save the map under Mod\Data\Art\MAPS
Again, if you have trouble understanding the instructions or any of those programs, seek help from those with experience.