You can use baby nail clippers or just regular small (hand size) clippers to nip the sharp end bit off of their nails. Just be careful not to cut too high up as that could be painful to them. If you run the clippers along the bottom/inside of their nail toward the tip, you'll feel it sort of catch toward the very end. That's where the sharp bit starts and you can cut from there. It's just a very small amount in most cases.