Step up to a project to build a porch stairway with pre-made stringers secured with lag screws at the top and supported on a concrete paver landing at the bottom. The porch stairway will be constructed of treated lumber stringers, risers and treads secured with stainless steel screws. Four-by-four posts support stairway rails that tie into the existing porch.
Level pavers at the correct elevation with sand and attach a constructed ledger to the porch rim joist with rust resistant screws. Both have to be positioned properly to support the ready-made stringers purchased to build the porch stairway.
Position the four stringers for the porch stairway with joist-hangers while drilling pilot holes for lag screws through the rim joist and end of each stringer. Remove the joist-hanger and enlarge the holes for the lag screws.
Insert the hex head lag screws from the back of the joist/ledger and into the stringers to permanent attach them. Tighten each with a socket wrench. Repeat for all four stringers to support the porch stairway.
Install the risers for the porch stairway with stainless steel screws that will resist rust and corrosion in the salt air. Drive them through the riser into the vertical edge of the stringers.
Add all but the bottom two-by-twelve pressure-treated treads, centered so that the overhang is the same on each side of the porch stairway. Drive screws through the treads into the middle of each stringer to secure each.
Use a reciprocating saw to cut away the existing rail from the porch and make an opening to access the new porch stairway.
Add the bottom four-by-four post to support the porch stairway handrail. Clamp it in place and use a level to insure it is plumb. Drill holes for carriage bolts and snug them with a socket wrench.
Trim the cut ends of the railing to length with a Japanese hand saw and round the ends with a jigsaw. Notch the ends of the bottom tread in the porch stairway to fit around the post.
Angle the rail on the porch stairway by measuring the same distance up the posts to the bottom of the rail. Use a bevel gauge to transfer the angle to the power miter box and the miter the ends.
Use a Japanese handsaw to cut the post top to the same angle, and then add the upper rail and its top. Add the bottom rail. Repeat to add rails to the other side of the porch stairway.