Given that Christmas Eve is December 24th, this one should be rather self-explanatory. Just play a round on that day and carry out a Heist in the Slums collecting 100% of the loot, and you’ll unlock this achievement.
It might not unlock immediately, especially when you start a new game, but the second Heist in the Slums should do the trick.
You can probably change your computer’s date to December 24th, if you don’t want to wait for Christmas. But since this is generally frowned upon, do so at your own discretion.