They can either comply with the new laws or become illegal gun owners that get found and charged like any other illegal gun owner.
Of course, the "are you going to take them? " isn’t meant to be a logistical problem, it’s meant to be a threat.
If you want to fire on innocent people because you didn’t like democracy, go right ahead – it’s not like legal gun owners aren’t doing that every day already.
At least it will be the cause of the problem dying in a hail of bullets, rather than innocent people.