Prefab texture edit

[iRizzo24]

Hi there, I hope that someone will answer me.
In these days I learnt how blender works and I have done more than 50 new italian realistic signs that I'll share here in the next days.
But now I would like to edit some road prefabs: I saw that iberian dlc has a lot of new prefabs really useful and I want to make it usable also for italian dlc, so I should edit the asphalt textures to make them compatible with italian roads. I will learn by myself how to work with prefabs in blender, but I first need to know what is the correct workflow, cause I saw that prefabs are more complex than signs, also in def files. Please let me know something, I'm working also for you cause I'll share everything, but with your help everything could be easier and faster.