water change. what you do with the water depends on where you are and what you have planted. If you get a lot of rain and have salt tolerant plants you can dump there. salt is really mobile in the water column and can be dilluted. If you want to be totally safe, dump to the street

what is going to happen to the pond depends on how much water there is and how much salt was added. salt can be beneficial depending on the concentration. iow a little salt can be good but a lot of salt is bad.

You didn't include crucial info such as how big the pond is, but I sense this is a full out crisis for everything for fish/frogs/plants/bugs and yes even the snails in time. Beneficial bacteria will surely be destroyed as well if this isn't dealt with asap.

I also suggest a major water change, and if you still see crystallized salt to shovel and scrape all that is visible.

Id refill the pond (using chlorine remover), and possibly flush once again. You can buy beneficial bacteria at any pet store, I'd dump some in.

Disposal? On your driveway or paths?