Opening space under stoop

I would like to open up the space under our stoop for bike storage etc. I see many people with open space under their stoops and a few that are like mine.
Obviously, you need to have someone do it who won’t knock the whole thing down. I’m replacing a sidewalk square in the front of the building too and have gotten a few names of contractors from Brownstoner for that.
Has anyone else done this? Or have any advice they can offer. It seems that it wouldn’t be much more than a cautious demo job but I can’t be sure.
Thanks for any advice.