Originally Posted by toytime
Until a couple of weeks ago, I was like you Pablo, thinking that the pin end was "rounded over" or mushroomed. From what I learned the pins are not like this at all and even grinding is not needed. That is why a punch and hammer works. It seems to be a friction fit.
You are exactly right- a chain breaker is great, but a punch and hammer works fine. I never grind the end of a pin. If you do, it may not hold well if you try to reuse it....which often happens. To use a punch, just put the link up on an old small socket so the pins has somewhere to go, put the punch on the pin, and drive it out.