The tool in this photo works great to remove caulk.
caulk removal tool.JPG
It's next to a popsicle stick to give an idea of the size.
I've removed a lot of caulk over the years and those little plastic or nylon tools work the best by far. A key to success is to work on a 1/4" or 1/2" at a time and it comes off fairly cleanly. If you try to brute force it the caulk seems to fight back and adhere stronger and or break. If you work just a little bit at a time it releases
with less effort.
I got the tools at an RV place where I purchased new caulking.