Hands down toughest achievement in the game. This will take a few attempts and is pretty bloody annoying. You need to do the level under 1:45 and that's no mean task. My best time is 1:37 and that took a LOT of attempts. You want to be dropping down the hole at around 27-28 seconds. You then want to try and get up onto the left side of the hole tunnel in one go. Swing to the right and then straight to the left. If you get it just right you will save a lot of time here. Bait the first 2 birds and hopefully be at around 1 minute or under. Ensure you have enough snow in the snowball to cross the twig bridges and bait the next 2 birds off the edge. Roll down to the ice where they spawn and then dodge to the side. They should both be down at around 1:30-1:34. That gives you just enough time to roll to the exit.
Stick with it, this is tough but once you get the rhythm of things, it's not as bad as it seems.