Catwalk and Staircase Renovation

I purchased an existing house and would like to modify the following things: 1. The removal of the existing 1st to 2nd floor staircase in order to install a wider stair with different design. 2. The removal of the raised 2nd floor bridge and structure in order to install new bridge at the typical 2nd floor level so there are not any 3. Removal of a portion of kitchen wall in order to "open up" the kitchen to the family room.