I recently bought this Uncirculated 1964 Kennedy Half Dollar in an acrylic triangle and I wanted to break it out. Here's how I freed it. 1) Using a hand drill I made a series of holes directly above the edge of the coin. I repeated this process on the bottom continually checking that I'm not hitting the coin with the drill bit. 2) I cut two grooves on either side of the block to connect the end holes. I also cut across the two sets of holes. 3) Using a hammer and a screwdriver as a wedge, I started to crack the block. Using light taps I was able to crack it in two. My goal is not to force the screwdriver all the way through (and thus, damaging the coin), but rather to create tension and allow it to break on it's own. 4) The coin is still stuck fast, so I used the same process to now split the half-block. 5) This being successful, I was able to remove the coin with a gloved hand from the clinging remaining chunk using light pressure and pulling. Viola!
Yes... but why? You had a cool paperweight... now you have a generic half dollar. I don't understand why you chose to do this.