How to Create Texture Mods?

[DefenestratedKoala]

So I'm looking to change the weapon tint system. Instead of blue/brown/red, I was hoping to make them shades of grey (I still want a visual indication for them on some weapons.). How would I get the textures for each weapon mod extracted and what would the texture names be?

 

Additionally, how would I make the barrel attachment for certain weapons invisible, while leaving it visible for others? (Ex: make it invisible for the Avenger, but leave it visible for the Revenant)

 

Thanks in advance!