I cut 5″ flashing from a sheet of 8′ tin. We bent the tin and attached it to the stud wall footing. We cut one inch rough sawn siding to length and nailed it into place.
We finished the wall. We cut two inch lumber, squared it and anchored to the wall, and built the first part of the framework for the landing from these. We hauled the stairs to where it would be placed and set up the second part of the landing, secured it to the first, and then worked the stairway into place.