How do you play lich king on wow with new patches for cata

If your account is flagged for Wrath of the Lich King, but you did not buy Cataclysm, the game works as normal. However, you will not be able to make Goblin or Worgen characters, learn Archaeology, level above level 80 or access the Cataclysm zones.

All content that existed prior to Cataclysm is still available to you, including the revamped Old World questlines and zones. These are available to all players regardless of which expansions they bought.