The lta export script goes in this directory (or something similar) -- C:\Program Files\Blender Foundation\Blender\.blender\scripts
I cannot possibly explain how to use blender, so it is up to you to search for tutorials for it, but I will still try to show any shortcuts I use.
First, find an LTB which you wish you to change. For this tutorial I will be using PV_M_DOTB****b
Using ltb2x, convert the ltb into a directx(.x) file.
Now, open up blender. Press delete to delete the default cube mesh you see on screen. Press file -> import -> directx(.x) and then browse to the .x file.
Someone like this should show up:
You can zoom in using the mouse wheel.
You can either add to the mesh, or make a completely different one.
I will show how to add onto one.
Press space, add -> mesh and select something. Press S and move the mouse to scale the mesh.
To move the camera(so that you can see the object from different views) you can either press view and select top,side or front OR you can press shift+f to go into 'flymode'. You can move the camera by using wasd(forward,left,right,back) rf(to go up/down)
Now, lets say I want my scope to look like this:
Now(while holding shift), right click on the cube, then the scope and its other piece, in this order! Press ctrl+j to join meshes. Then press TAB to go into edit mode. Press ctrl+t (the exporter needs you to do this)
Press TAB to go back to object mode.
Before you export, press ctrl+a and select scale and rotation to obdata. Make sure the mesh is selected, and go to file -> export -> ****a file ( dont forget to make it ****a)
Open up Model Edit. Press file-> open and select the ****a you have just exported out of blender. When the 'resolver invalid anim dims' pops up select Use Z. Press File -> save and open the same file again
Now press file -> save and compile. Select where you want the ****b to be saved. Now you rename the file and inject it into a .rez file
Sometimes, the model may not show up in game. If that happens, you would have to start all over again...
Note: You CANNOT make different guns using this because it does not support animation.