Measure the height of your trash can, from the bottom of the can to the bottom edge of the rim. This is how deep your hole should be. Measure the diameter, or how wide it is across the top. Add 4 inches to the width.
Dig a hole in the ground that is as deep as the measurement you took of the can's height. The hole should be as wide as the diameter of the trash can, plus 4 inches. Dig the hole in a dry spot that does not collect standing water.
Lower the trash can into the hole. Fill the gap between the can and the walls of the hole with soil. Firm the soil as you pour it in by tamping it down with the handle of the shovel.