The lights are on
[SPOILERS] With the impending release of Mass Effect 3's ending DLC, players might be wondering how to access the new content.
To experience the Extended Cut, load a save game from before the attack on the Cerberus Base and play through to the end of the game. The Extended Cut endings will differ depending on choices made throughout the Mass Effect series, so multiple playthroughs with a variety of different decisions will be required to experience the variety of possibilities offered by the new content.
To learn more, check out this handy FAQ from Bioware.