You have to realize that when Trump is 'off script,' he talks like a rude New York working man in a bar. He does this in part because it is his nature to be rude and vulgar, but also because he realizes that this helps him gin up his base.
Let me try to put his point in a more 'measured' way. His point was not that Hillary's bodyguards ought to be disarmed so that she could more easily be 'taken out.' His point is that if guns cause crime and have no legitimate uses, then why are her bodyguards armed to the teeth with the sorts of weapons that she would like to make it illegal for law-abiding citizens to possess and carry?
If guns are never the answer, why are they 'the answer' for government agents? If law-abiding citizens cannot be trusted with semi-automatic pistols and long guns, how is it that government agents can be trusted with them?
The graphic makes the point very well. Trump was not inciting violence. But if you say he was then you are slandering him and his supporters. Be careful, the Second Amendment types may 'come after you.' Politically.
UPDATE (9:25 AM). Here is what Trump said:
She [Hillary] goes around with armed bodyguards like you have never seen before. I think that her bodyguards should drop all weapons. They should disarm. Right? Right? I think they should disarm immediately. What do you think? Yes? Yes. Yeah. Take their guns away. She doesn’t want guns. … Let’s see what happens to her. Take their guns away, okay? It would be very dangerous.