Deviljho is one of the main mods for Monster Hunter: World. 

First of all, you need to download the main Monster Hunter: World mod file from the official website.

When you have downloaded it, you can start the installation process. The first thing you need to do is to go to the Monster Hunter World folder on your drive. This is the place where you will find the mod files.

After you have found the Monster Hunter World folder, you need to unzip the mod files. You can do this using the built-in unzip tool from your operating system or using a third-party app.

Once you have unzipped the files, you need to drag and drop them into the Monster Hunter World folder. This is the place where the new mod files will be installed.