Neighbor OVER SPRAYED lawn with Roundup-killed my St. Augustine. What do I add to soil before replanting?

Last year, my neighbor sprayed Roundup on his entire lawn. We have connecting yards and the residual seeped into my yard, killing my lawn. The grass never came back this summer. I want to add minerals to the soil before planting new St. Augustine ----but am not sure what to put into the soil.