KEEP IT SIMPLE. JUST PUT THE LIGHTS BACK ON TO 24/0 TO 18/6 AND WAIT FOR HER TO START GROWING AGAIN. oops, it wont take long (3 weeksish) to notice new growth coming on.
then you can start to think about chopping her, use the bits you chop off as cuttings, if they take great, if not, never mind, nothing lost, everything to gain
wait untill the leaves start to go yellow, its not the best way to learn, but your going to have plenty of plant matter to work with once it starts growing again, and it will use up the nitrogen in it to grow