We wanted to place it in the ground, so first we flipped it upside down and carved the outline in the ground with the shovel. Then we started to dig it out.
As we got to right depth we started squaring off the sides. The tank could be lowered in temporarily to check our fit and depth. Leveling the bottom was a fair bit of work in itself, because of the rocks. I used a long board and a level with the tank inserted to verify that all edges were at the same depth. You can see the pile of rocks to the side. All smaller rocks and gravel were removed with the soil.
