Some maps have their main name (the one you're looking for) on war3map.wts,
But to have a complete name change on map, you need to edit "war3map.i", the .w3x map file and "war3map.j".
U can open those three files with HxD or with Notepad++.
Also there's some stuff on "war3mapSkin.txt" related to ingame texts, in dota for example, you have the map version there.
And if you want a complete name change work, you can also edit "war3mapPreview.tga" that's the map image.
If you still have trouble on changing map name, try follow this guide:
deprotection-cheating-f64/advanced-map-editing-t21344.htmlLook for fake version.