Watch this video from This Old House to learn how to install landscape steps.
1 Drive 1x2 stake into ground, then use straightedge and level to find height of top step; mark height on stake.
2 Use level to find height of grade at bottom; mark height on stake.
3 Measure between the two pencil marks to determine total height of all steps.
4 Dig two trenches at bottom for installing 6x6 sleepers flush with grade.
5 Use a circular saw and handsaw to cut 3-foot-long sleepers from a 6x6 timber.
6 Treat cut ends of sleepers with wood preservative.
7 Drill two 9/16-inch-diameter holes through the sleepers; position the holes 6 in. from each end.
8 Set sleepers in trenches, making sure they're level with the surrounding grade.
9 Use sledgehammer to drive 48-inch-long rebar through the holes in the sleepers and into the ground.
10 Set two 6x6 treads on top of the sleepers, forming the first step.
11 Place sleepers on top of first sleepers to support the second step.
12 Fasten the timbers to the sleepers with 10-inch-long landscaping screws.
13 Backfill around sleepers with pea gravel.
14 Continue adding 6x6 sleepers and 6x6 treads for each of the remaining steps.