Hi there does anyone know how to make the bottom part of the stair look like a ramp (see photo)
Yes, use Interpolated Curve tool and pick the individual points below the stair.
create 2 curves for the inner side and the outer side and loft them together to create the Helix
select the Helix and extrude it vertically to touch the midpoint then use Boolean union to merge the helix to the steps.