i wish to change gearment of some troops

do i need separate modding tool or can i just try to find right files and rewrite them?

I think, Morgh's Troop Editor will help you a lot. The Forge section offers the dl.

Here's how I do it:

Play the game with cheats turned on.  Use the cheat menu to access all of the items.  Take screenshots of all of the items in order (takes a little while).  you should get ~125 screenshots give or take.  Make sure you take screenshots of the pages indicating item number.  This will help you identify where you are later.

Use Morghs Tools and open the troop editor.  Find the troop you want to add/remove starting gear.  Using the screenshots of the items, you can figure out what you're adding/removing from the troop. 

It takes a little while to get used to but I do it so often that I now know most item numbers by heart ha ha ha.

good luck!

                Gearment
Garment Gear