You can't. It's not possible without having someone with a $20k license from Samsung purchase you a special certificate that costs $600. Anyone who tells you otherwise is either mistaken and thinking you are talking about sim unlock or just plain lying.i have the 960u also how did you do it? bootloader unlock.....
The only real route to a bootloader unlocked cdma Galaxy S* is to buy one from overseas. This worked great for the s9 as they sold them in South/Central America but with the S10 it was only China, so YMMV. Luckily Verizon now fully supports LTE only connections and even sells phones themselves without cdma, so if you aren't with Sprint you will be fine with an exynos. And if you're with Sprint, well change carriers ?