Certified GKH Gardening Expert
The most common way to lure snails from the leaves of your plants is to provide them with something to eat that they like better on the ground. You may have to manually remove them from the leaves at first - here are a couple helpful articles:
In addition, you may want to try some garlic spray: https://www.gardeningknowhow.com/edible/herbs/garlic/controlling-pests-with-garlic.htm
Pick them off and put them near the bait. Leaving them on the tree could damage or kill it. If you don't like touching them wear gloves or cut off the infected leaves.