How to change Texture Resolution? [Kinda Solved...]

[ezRAFA]

I'm playing this game at 20/25 fps and I'm prety sure that setting mentioned above is tanking most of my FPS, any way to turn that down? It shows as grey and I can't change it no matter what.

So I've done some research and the only way I could chnage is was by watching this video https://www.youtube.com/watch?v=zOS-8zhX8MM

Is there a way to change it in game like it should be or do I have to do it manualy?