no problem. At the moment you can't get rid of grass, it will always grow back.
We have plans to make it so you can edit any tile.
Thanks!
Just keep checking out the weekly builds. You can see what changes are made on the Change Log here https://docs.google.com/spreadsheets/d/1s2nIsLg-suLVX_O6MgDGtxZDLgmVXvwIzwauNDpU...