How to break reinforced Shimano pin? Sorry if my technical English is a bit imprecise.

I just put on new Shimano CN-HG53 chain. I joined the ends not with regular pin, but with provided reinforced one (like one of those below).



The problem is the tip (end) of that pin is entirely outside the link now, and I should break it off. But it is so well made, that I cannot do this. With bare hands -- not possible at all. With pliers



I move the pin tip up-down, but entire chain is rotating (even if I grab it with my hand). I could hold still chain with another pliers but I am afraid of damaging the link I would hold with pliers.

So what tool is required to break it off, and how to do it?
Ok, I did it! :-D I took two plates of steel, drilled a little hole in one of them (for the pin), then put the chain between them (pin goes through the hole of course). This served as vice, but because it was not mechanically clamped I could control the force.

Then I used pair of pliers, and without a sweat, pin snapped.

I used the same chain before, but I used regular pin, after a year it came out of the chain (partially), thus this time I used reinforced one. We'll see how good it is...