It possible to edit an existing mod/kit?

Hi, I recently started using a mod for BG:EE (rogue rebalancing). Now i love the mod but one of the kits that were edited (bounty hunter) was given an ability that isn't as useful as it should be. I was wondering if there is a way to go in and edit that ability that was given by the mod. And if there is how would i go about doing that?

I'm new btw, so if this is common sense easy stuff i apologize.