If you don't want to reset the Xbox system time to keep the lives you already have, during a level if you know you're going to fail or do in fact fail. Don't continue after the 'Out of moves!' screen, as that will remove your lives.
Just press the Xbox button
, then 'Start'
and quit to main menu. Launch the game and play the level again you'll have the same amount of lives before you started that level and the level will have been rearranged if you had a poor arranged one before!