Track can be found here: https://www.racedepartment.com/downloads/hillclimb-los-marteles-up-down.5134/
- You should be able to copy the files straight into you assetto corsa folder as long as you have the track installed. It will ask to override - backup your track if you want to keep the original files.
- If the new grass still won't show check your assetto corsa folder: extension/textures/grass_fx. You should have a "highlands.dds" file in there, otherwise no grassFX.