not going to happen without the house agreeing
He doesn’t need the House.
He just directs the BATFE & Co. to stop approving anything needing their approval. Stop NICS. No approvals of FFL licence renewals (take custody of Yellow Form files with extreme prejudice, of course). Don’t have to ban anything, just have to make the system grind to a halt. Let objectors sue. Tie it up in the courts. Drive it, for years, to a Supreme Court which has already been bought off.
Congress handed practical control of the Second Amendment to the Executive branch long ago.