To install a concrete storm shelter, dig a hole that is large enough for the shelter, set the shelter into place with a crane, and cover the storm shelter with backfill. Concrete storm shelters typically require installation by professional installers.
Check the ground to ensure it is dry enough to accommodate heavy machinery before moving the storm shelter into place, and use a backhoe to excavate an area large enough to accommodate the shelter. Remove any large rocks unearthed during the excavation.
Use a shovel to manually level the dirt inside the excavated area before setting the shelter in the ground. Complete any required assembly, and anchor the storm shelter into place following the manufacturer's instructions. If recommended, add concrete filler around the storm shelter, and cover the shelter with the required amount of soil.
To install a storm shelter inside the garage, measure the amount of space needed for the shelter, and remove the concrete from the garage floor. Dig a hole that is slightly larger than the storm shelter, and set the shelter into place. Complete any required assembly, and add the required amount of concrete backfill. Smooth the concrete, and allow it to set for the recommended amount of time.