Just in case you don't know, there is a tool for that purpose and it isn't a plier. I'm pretty sure I bought mine from MidwayUSA. It fits every S&W frame size ejector rods and removes any chance of bending or marking one.
Or you can chuck it in a drill press being careful not to bugger up the rod end knurling,
More importantly putting spent casings in the chambers so you don't damage the extractor star.
Definately watch a few tutorials on YouTube before attempting.