Build hinged deck trapdoor with ladder access below

I’d like a hinged trapdoor built into my existing deck in Elanora Heights, with a ladder or steep stair underneath so I can climb down to the space below. Opening approx [width] x [length] cm, positioned [where on the deck]. Drop from deck to ground is approx [height] m. The job: Cut the opening in the decking. If any joists or purlins need cutting, they must be properly trimmed with headers to maintain the deck’s structural capacity. Please explain your approach in your quote. Support all cut board ends with blocking and fit a frame/ledgers around the opening. Build a hinged lid from the cut-out boards, joined with cleats so it sits flush and doesn’t rock, with standard board gaps for drainage. Use heavy-duty exterior hinges (stainless or galvanised) and gas struts or a locking stay so the lid holds open securely. Fit a flush or recessed lift ring and a latch so it stays shut when closed. Supply and install a fixed ladder or ship’s ladder below, rated for outdoor use, secured top and bottom, with a handhold for getting in and out. The deck is framed with steel purlins and beams, not timber joists. Any framing changes must use steel brackets or suitable fasteners, and existing steel and its coating must not be cut or drilled without an engineered detail. Please only quote if you’re experienced with steel-framed decks. Licensed carpenter preferred. Please quote including materials and let me know if you’ve done similar work.