How install it on your server:
http://wiki.garrysmod.com/page/Workshop_for_Dedicated_Servers

How to mod it:
Check out the lua/autorun/rb655_lightsabers_modding.lua file in the addon.

Hi rubet thanks for helping I've done that but cannot edit the gma file do I extract the gma to a file and put in addons?

I don't provide support for actually editing my mods. You can view the modding instructions by either extracting the addon and locating the file, or by opening the .gma in notepad.

Same goes for editing the mod, you can extract it and edit it, but I am not going to do any of it for you, nor am I going to provide support if something doesn't work or breaks while you are editing it.