Thank you for your comment.

A lot of times, the pins for Casio buckles aren't the spring bar type like the ones on the white watch are, but instead they're pressed in. I've been able to get them apart with a pair of needle nose pliers on each side and just pull apart. They're kind of tricky though so be careful not to pull them apart too aggressively or you could end up breaking the buckle. Just be ready to stop as soon as you feel it starting to give, because once it does, it comes apart very suddenly.

Thank you for your comment. I used a Parts Cleaner Spray.

You can also you either Goo Gone or Goof Off. They're both adhesive removers and they both work pretty fast, so access to clean, fresh water is a good idea just so you can rinse quickly before it starts attacking the finish. Some people use 100% acetone nail polish remover, but I really don't recommend it. Every experience I've had with it has resulted in a ruined finish before there was ever even a chance to rinse; like literally within one second. If you have the black watch, it isn't too bad and you can usually get to it before it damages the case color. If you have the silver toned watch, it'll destroy the finish immediately, like before you're even finished with the lettering, the silver paint disintegrates and leaves you with a white housing. I have a silver one where I wasn't fast enough and some of the silver came off and exposed the bare white plastic, but it left a ghost image that still says ILLUMINATOR, even though the silver paint is gone. Whichever product is used, you want to work quickly and not bear down too hard on the Q-tip, because the harder you press down, the faster you'll eat into the finish.