The first thing I recommend is taking a few steps with your 24 kg kettlebell overhead at the end of a set of presses. Work up to taking a short walk with the kettlebell overhead. Practice this with 16 kg if you haven't done it before, then move up to 24 kg when you're ready.
The second thing is taking more walks with your kettlebell at your side. The same guidance applies - if you haven't done this, use a 16 kg or a pair of 16 kg to start, try to work up to walking 100 meters or so, roughly a minute and a half. (Your overhead walks will likely be shorter and that's OK but you can work on increasing the time on those, too.)
These things are prerequisites - you want a stable shoulder and a stable body under your shoulder, and a strong grip, and you'll get those things by walking around with your kettlebells.
As to the snatch itself, trying to resist the force of the kettlebell on the way down is worse than catching it with a straight arm.
When you are ready, which means you can do the walking described above with 24 kg, go outside and practice lowering your 24 kg snatch directly to the ground - just don't bother to try and catch it at first, and eventually you'll figure out how. Remember to be safe and make sure you're outside or in some other place that lets you get rid of the kettlebell as needed. Once you get the hang of having it come down, try steering it so that it ends up behind you so but still let it go. Eventually, you'll figure it out. Try these drills with a 16 kg first if you've never done them before, please.
A video of you snatching a 16 kg for a few reps would be helpful if you can post a link here.
-S-
