There are a couple good options. You could get 2 assissin snails if you "never" plan on putting any type of snail in the tank again. The assissins will kill and eat all the other snails.
Option 2 is very simple. Get a glass jar, then cut a slice of zucchini about 1/4" thick, microwave it for a few seconds to make it slightly soft (you don't want it to be mush and fall apart so literally a couple 2-3 seconds should work). Rubberband it to a small flat rock or something that will hold the zucchini down since it will float, then lay it in the bottom of the jar. Put the jar on the substrate where it is easy for you to take it out. Be sure to lay the jar horizontally, don't stand it up. Do this once the lights are off, and even turn them off early so you can get a good start. In a couple hours reach in and carefully stand the jar upright so the snails fall to the bottom and lift the jar out. Dispose of the snails and put the jar back in. I don't know why snails like zucchini so much but they really do. You should be able to get tons of snails out and all it's going to cost is the price of a zucchini or two. I use this method if someone asks me for MTS snails.