Keep it in as much light as you can until spring, and don't over water it. Get it outside in the sunniest spot that you have after the last frost. It may go dormant a little earlier in the summer, or early fall, but should come back just fine next year. They are very hardy.

Let the top growing portion of the lily dry out and whither or just cut it off and after that happens cut it at 1 inch above the bulb .Place the bulb in a ziplock bag with peat moss that has been moistened about what half of coffee grinds would look like after brewing and place it in your refrigerator for 6 to 8 weeks and if you place it in the ground in Z6 where you live your plant will think that it is spring again and go into full growth cycle.Always a south facing wall in our climate if not east is best secondary, good look my friend!