Download the Technic Launcher from the official website.
Run the Technicpack launcher and sign in with your Minecraft account. Then click the "Modpacks" tab.
Click the following url to copy it and paste the URL into the search bar on the Technicpack Launcher. http://api.technicpack.net/modpack/pixelmon-251 or search for "Atlantean Pixelmon"
Click install on the modpack page
Launch the modpack through the Technicpack Launcher and join our network! Our server will already be listed and ready to go.
Good luck with your Adventure!