The SiboRoc Launcher is available on the home page of the http://siboroc.net site. Near the bottom right corner of the page is a link for Launcher. 1. Click on the link Launcher. Let it download the jar file to your PC. 2. Run the Launcher. (just double click it, your Java JRE will take over and execute it) After the Launcher starts up, it will fetch the latest mod pack listings from the server and display the mod packs in the left panel. Take care to choose the version of the modpack you want. Some mod packs are revised time to time. The Launcher works the same way most other launchers do (think: FTB, ATLauncher, etc...) so it will pass your authentication details to Mojang as you've done with the Minecraft Launcher, FTB, ATLauncher, etc.. After some time the SiboRoc Launcher will complete downloading all the assets, start Minecraft and then continue the process of setting up your instance of the modpack. If you've already downloaded the modpack this way, the next time you choose to play the modpack, the download phase will be abbreviated (just like any other Launcher). Questions/Issues? Please post them here. Thanks.