I used to use a thick long screw driver, I don't know how safe it was, but it never came out. J.R.
I always just took another pin out of another machine or stack if it didn't have the little cable attached and stuck it in about 1/4 the way down the stack. Most hold 2 (45's) not problem however it does slightly bend the pin and the plates have fallen off before so make sure the area is clear.
One extra 45 might not make it happen but I hope no one gets a snapped cable in their face lol