Aftershock mod trouble

[eroseland]

So let me just start by saying I know VERY little about this whole modding thing. It's my first attempt, so, yes I went a little overboard just to see what I could do for my first try. I'm not all that brave so I took the weapon rebalance mod, and basicly copied and pasted and added the weapon to the very end of the equipment.txt file, repacked, crossed my fingers.

 

My problem is this: how do I even GET the weapon to see if my changes work? Is there some way I can edit what my store has and add my custom weapon to it?