Can I simply replace a material with grass?

Hi I have a golf course imported from 3dsmax with several materials on it. I would like to replace them with different grass materials (real grass) I have some grass packs. But pulling them into the material slot does not seem to be the right way. Trying to avoid using the paint tools. How do i do this properly? thank you!

I dont find the procedural grass tool effective personally, but there are tons of tutorials out there explaining it.