We are staying at an rv and I left the litter outside for our cat to use, it starring storming and I panicked instead of bringing it inside then throwing it away I just threw it in the grass.. Now I know my mistake but I don't know how to clean it

Don't cut up your grass. The litter will degrade and disappear in a lot less time than it would take for new grass to grow in that spot. Even clumping litter is really just clay and should not kill the grass.

I'd wait and see if you can remove more once it dries more fully. I wouldn't actually carve out your grass. It might kill your grass, but I'd wait for that to happen first.

Scoop as much as you can and leave the rest.

When cleaning out the litter box, I accidentally spilled a bunch of litter in the backyard. I tried to scoop up as much as I could, but still left a bunch. Then it rained. Now it's a muddy, sticky, gross mess. Note to self: rain does not make litter clump up and removable.

Am I going to just have to carve out that whole big chunk of grass? Is there any other solution?