I've already got my new weapon file, just how do i add it into the game? I have no idea were to put it

You mean you have the .odf for your weapon, correct?

If so, you just replace one of your map's units' weapons with it.

Aka if you wanted to replace the Republic Soldier's Primary Weapon with your weapon you'd open up the Republic Soldier .odf, and replace
with
Also, this is rather crucial as well (:P), to put your .odf and any related files (the .msh, .ord files, etc.) in that side's folder.

Oh, and also then munge with the Side selected for your munge.

sorry, were is that script file?

your units odf file example: rep_inf_default_rifleman (unit's weapons) rep_inf_ep3_rifleman would be for how it looks
if you dont know what im talking about look in the everything you need to know thread under custom side: how to