On the level ground next to the Bricks place 2 sticks or pole with the string going across the center of the ring with a certain height so you know that the opposite side is level and go around the ring up and up a few inches to reach desired height. You use the mud to reach the string line so your not having to have to move the string to the rock to make it look right. I hope i explained it from my pov clear enough😂
