You're shitting me, right? You think that editing models can give you a 'MACRO?' lolwut...............................
Let me explain some things.
First off, the Unreal Package (.upk) files that AVA uses are post-bake. You can extract them, yes, and you can view them, yes, but you CANNOT repackage (bake) them or edit them (and then re-bake them). People have been working on this ever since AVA came out.
Secondly, Even if you changed the size/shape/color/whatever of the models, it wouldn't change anything, since the hitboxes remain the same (GL editing those, mate). Also, changing models is client-side only. No matter what modifications you make to your models, the server still displays the correct models to everyone else (only you can see your changed/edited models, nobody else can).
A macro is not model-based, it's code based, simulating keyboard and/or mouse input.
Now, in theory, you could edit the coding embedded in a .upk to change what gun it displays on your screen, but you'd have to extract, edit, and re-bake EVERY model name (every object attached to a weapon, including everything corresponding to animations, for reloading/switching/etc.) which would be so time consuming for only a graphical change (since the performance of the gun would not be changed, unless you edited attached gun stats. Then again, if you don't do that you'll get an error also).
Trust me. I've tried EVERYTHING I just said. At one point, I actually got my SAKO to be an MP40 by editing EVERY part of both files with the Unreal Development Kit (UDK) and ArtMoney. It was so time consuming though, and you had to rename all the different parts (i.e. "SakoMagazine" > "MP40Magazine") EVERY game you played ingame.
It's going to be impossible to do that now though, since the new AC Aeria is bringing in supposedly will be running hash checks (best of luck spoofing a hash check).
Also, these Gildor utilities have been around since the dawn of AVA. So, no newsauce here. They're cool for viewing models and animations, but that's it.
Best of luck!