Originally Posted by DannoXYZ

There's a lost-art to using a pin-tool to push out a pin and re-joining the chain later. Most people are too brutal with the tool and end up damaging the chain and/or pin in the process and end up with self-destructing chains later. While the swagged & stepped ends of the Shimano chain-pin does require a special replacement-pin to be used whenever a pin is pushed out, I've done many a KMC chain without problems.

One of the tricks to only push out the pin just enough to get the inner link out. That's typically 9 half-turns of the pin-tool on an 8-spd chain and then you have to flex the chain sideways to open up the outer-plates enough to get the inner-link out. A lot of people push out the chain an extra 2 half-turns so the pin is flush with the inner surface of the outer-plate. But I suspect this may expand the hole a little too much. Or they push the pin out completely and end up mangling the side-plates trying to get the pin back in.