This glitch will allow you to get all of your lives back in 2 minutes instead of the 2.5 hours the game normally requires you to wait. When you have 0 lives:
1. Close out of Angry Birds 2 (delete it from background)
2. Open up your settings app
3. Go to General, Date & Time, Uncheck Set Automatically, and set the time ahead 3 hours. (For android just look for the Date & Time setting)
4. Enter in to Angry Birds 2 again
5. You should have 5 lives!
Watch the video below if the steps above were unclear