How to remove shine on terrain textures?

All other tutorials have not worked

I am new to terrains on Unity, and I am having trouble with removing the shininess on my textures. In the add texture pop-up, there is no smoothness slider, and no alpha box. The tutorials I have tried seem to be a bit outdated. I am using Unity 5.5.1, and any help would be great. Thank you in advance.

If there is no setting for smoothness in the texture painter on the terrain, it means that the texture you are using has some form of alpha enabled. Select the texture in the Asset/Project browser, and under “Alpha Source” select “None”. Now you should be able to adjust the specularity of the terrain on a per texture basis.