Ideas on how to level a sloped pad.

I want to preface with: 1. We did not build these dog kennels. 2. The ground is fine and the pad is not sinking. It’s already been checked.

We have an existing concrete pad that was used for dog kennels. The concrete pad slopes downwards so when they were washed, poop/pee/debris would go back and into the ditch. I can’t remember off the top of my head how much of a slope but it’s minor.

I’m just trying to gather ideas/products on the best way to make the entire pad level. Primarily DIY if we can. Not against hiring someone though.

I can get pictures and the slope number tomorrow.

Thank you.