Make a new match. Choose an AI opponent (click the arrow next to its name and add it to your team's color, should be red by default I think). You can click on a name and click on the map to choose each player's territories. It works best if you choose Europe for yourself and China for your ally.
Once you are in the game place all your buildings in your territory (works best if you group them up) Press the advance time key (>>>) to reach defcon 1 quickly. Once you reach Defcon 1, right click your silos to turn them into nukes (top option) Each silo has 10 nukes. Select your silo and click on the ground to launch the nuke towards that area. Better wait till Santa is flying through Europe, as nukes have to travel less, and cover more ground with the explosion. Just anticipate Santa's trajectory and nuke the hell out of him.
Easy.