So, second newel in place. You can see the new structure - 2 2x4s, construction adhesive and bolted into the joist, then the newel is adhesived and bolted into the joist and into the new 2x4 structure, then new floor boards put in. There will be 1/4" facing over the new and old structure to make it prettier (2x4s are ugly, especially with big bolt holes)