Client
- Download and run Forge Installer, select Install Client and click OK
- Run Minecraft Launcher and select Forge profile
- Click Edit Profile and then Open Game Dir
- Create or open a mods folder, and put the mod .jar file inside
- Return to Minecraft Launcher and click Play
Server
- Download and run Forge Installer, select Install Server, choose the location and click OK
- Create a mods folder in the server folder, and put the mod .jar file inside
- Run forge-<version>-universal.jar to start the server
Music Resource Pack
Since version 1.8.5, the custom music is a separate resource pack.
- Run Minecraft, go to Options > Resource Packs and click the Open resource pack folder button
- Download the resource pack and place it in the folder
- Go back into Options and click Resource Packs again to refresh the list
- Click the pack logo to enable it
Software Requirements
Hardcore Ender Expansion requires Java 7 or newer. If you are not sure about your version or are making a modpack, download Java Version Checker and install it the same way.