How to change textures in gta sa ios?

Question

Android

How to change textures in gta sa ios?
Here is a post , read it, tried it, but got stuck on this point.
There is a car, it drives correctly, it does not roll over, but where are the textures? Next to the img archive was a file with the pvr.dat extension ....
I don't understand how to replace the textures, in which file they are, and so on.
Could you describe this point in more detail, I would be very grateful.