By default rocket loader is installed on the server but it gets disabled when you run a "steam update". So, after an update, reinstall rocket loader from the control panel> game mods. You can also reinstallit simply to update it.
Once you are sure that rocket loader is active you can install plugins for it. You can find the plugins on this page:
https://dev.rocketmod.net/
Download plugins on your PC and unpack them if they are in .zip format and then upload them to the server via FTP (faster) or using the "file manager" from the control panel into the following folder:
/Servers/Public/Rocket/Plugins
Simply restart the server to enable the plugins you just installed.
