Before demolishing, place on the lower floor mason struts, wedged between wooden battens, all around the future hopper.
Dismantle the floor filling until the load-bearing beams of the floor appear. One of them is here in the middle of the hopper.
Descend the joists anchored in the load-bearing masonry with a perforator-chisel. Remember to control the shoring beforehand.
Place props under the floor over the entire length of the beam before cutting at the other end of the hopper.
Position a trimmer (perpendicular beam) at the end of the hopper.
The objective of the operation: to take over the load of the cut beam.
Perform welds at all junctions of the header with the metal beams.
Seal the ends of the supporting metal beams in the load-bearing wall.
Then all that remains is to finish around the hopper.
In this case, the thickness of the beams is filled with plaster smoothed with a trowel.