Posted By:
Anthony S.I've cracked maybe 200 slabs and have never damaged a single card. Once you get the case open (wrench at the top left corner of the slab) insert the screwdriver with your thumb and forefinger far enough down the screwdriver shaft (maybe only about the bottom half-inch of the screwdriver blade showing) so they act like a guard. That way you can never touch the card with the screwdriver. Please note: I'm referring to cracking tobacco cards. With larger modern cards you can't stick the screwdriver a half-inch while moving down the side of slab.
Buy a few uber cheap slabbed cards on ebay (new super shiny stuff), maybe one or two from each company, and give it a try. It's completely understandable you're nervous about damaging your cards, but everyone is the first time they try it.
edited to add: My unslabbing fee is 10 cards per six-pack. 15 cards if it's Sierra Nevada. 2 cards if it's Miller Genuine Draft.