The history of Marxist regimes and Socialist Utopianists provides the blueprint they almost always follow regarding the disarmament of the citizens they intend to subjugate to absolute tyranny.
But considering we are an anomaly with rights enshrined since our establishment - makes your question a bit trickier to answer - but I believe we will see a combo of what was done in the UK and Australia in the beginning, followed by what every despot from Hitler to Pol Pot did to enforce disarmament upon their own people.
They will ban the ability to purchase just about every conceivable firearm able to hold more than 5 bullets and isn’t a bolt-action/semi-auto. Ammo will be prohibited for ‘assault rifles’. This may happen in the next few weeks or months.
On the heels of that, or as part of whatever ‘act’ they conceive - a national gun registration program in conjunction with or mandated to the states and local police will also be enacted. A limited time will be offered to comply with the new ‘law’ before penalties for failure to register your weapon will be imposed.
Get another false flag or mass shooting, the opportunists will seize on that panic to demand a ‘gun buyback’ similar to what the Brits and Aussies suffered. The ‘buyback’ will be mandatory and because the government is ‘compensating’ you for your firearm - it will be said to pass Constitutional muster. They will give an limited amnesty time for compliance.
After that - look for penalty enforcement for turning in your weapon to begin. They will begin with fines, jail and seizures of property for non-compliance. You will be bankrupted and unable to transact business - I would not be surprised if the IRS is already a mechanism they will employ for enforcement via seizing bank accounts and wages for failure to comply or produce a weapon with a 4473 in your name.
After that - any resistance - and for public effect - to create a climate of fear, examples will be made of those who resist.
And then the rest of the sheep follow to avoid becoming the new Jews of the MarxoFascist state being erected around us.
We're already the Jews of the MarxoFascist state. They just haven't started the exterminations yet.