To install a Minecraft modded server such as Pixelmon on MCHub servers, you need to first locate your Game Mods in your control panel.
Step 1. Stop your server.
Step 2. In your TCAdmin Control Panel, select Mods
Step 4. Click Install Tekkit. Your server will be stopped if it is started and data may be wiped, depending on the mod that you install. Please BACKUP First!
Your server will now automatically restart and be converted!
You will need a client to log in to your new modded server. You can grab the zip file from here