They don't need a license, as far as I know, but it took me forever to figure out how to get it to work. Here is how I got it to work (if you already know this stuff, I apologize):
Start making the pack as you would for vanilla ("pack.png", "pack.mcmeta", and the "assets" folder). Because it is for 1.7.10, however, the texture pack must be of type "1" (defined in the pack.mcmeta file). Once you do that, you would go to the "assets" folder, create a new folder, and name it "lotr" (instead of "minecraft", which is what you use in Vanilla). This "lotr" folder will contain all the folders and files you want to modify. For instance, to change Gollum's texture, you would put your new texture in the mob\char directory inside the "lotr" folder. (If you unzip the mod file, the folders and files inside assets\lotr will be the same as they need to be in the resource pack.)
Hopefully that helps. If you have any more questions, or if that doesn't work, I would be glad to help.