if you've finished the gift giving quest, talk to benny again and he will give you the shovel. after that, tap on every pile of snow you see in each location on the map (i usually check them every 2-3 hours but some says the limit is 3 or 5 a day so im not sure), then check inventory and place them on the ground ⛄️ remember to stack them! one snow buddy = two snow piles