Well as mentioned in the original posting, I had a '63 Aaron PSA 4 that I decided to crack, and here's how it went.
The card started out looking like this. Decent card, nothing special but nonetheless a great card of an all time great player. To me, there's Ruth, Aaron and everyone else:
Here's my pliers right before I pin down the card with my hand and rip open a top corner.
Here's the result. Not so precise, but that crack that went down the face did not damage the card, thankfully.
Here's where I used a flat screwdriver to crack open the two plexiglass slabs sandwiching the card. This process did not go smoothly. I came very close to gouging the card several times, but I think the fact that the card was recessed kept me from gouging the card. The guy who said to use the putty knife is probably 100% correct. I need to get one.
Here's the freed '63 Hank Aaron. What a beauty!
And finally here it is after I put it into a different slab, a one touch that I don't particularly like (Oh the irony). But I do like the way it looks next to the other raw cards. And so, I declare mission accomplished!
PS: Note to PSA - please remove card from pop count data.