First, find yourself a taiga biome, not that hard, its not too far from spawn island.
Then, wait for it to rain (or snow in the taiga biome) and collect yourself some snow)
You can skip that if you have a glacial preciptator.
Get snow BLOCKS and place them around in the snow biome. light it up as efficiently as possible, no yellow crosses w/F7
if you have a mob grinder, this will go faster, but blizz WILL spawn eventually, or you can wait for night, get a power 5 bow, take away the torches
and just pop the non blizz mobs, then when one spawns, run in quickly with a safari net!
See, easy!