At the height of the porch, build out a 'landing' of sorts, that kinda extends the porch out (about the width of a new step) out and OVER the concrete. Then, from there, you can build your steps down.
As in this artists rendition:
================== ...Porch================== ...Porch================== ...Porch...============ Landing......======= Step 1......======= Step 2etc
You see, this way, the NEW steps won't be interfering w/the existing concrete steps.
Jay J -Moderator
The landing is just an extension of the porch
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