Pressing Piston Wrist Pins

I guess to be clearer would be if I asked just what it is that a machine shop is doing that cannot be done at home?
I do machine work at home, I have lathes and a Bridgeport, there's no magic done in machine shops, it's simply careful and precision work.
The UTG vid does mention a forge for heating up the small end of the rod, but as he displays, that's nothing really special.
Thanks for the input everyone!