You'll want to re-veg the plant first.
When you harvest, leave all the leaves and all the popcorn buds with their associated sugar-leaves on the plant.
Remove any seeds you find.
Flush the plant well if you even SUSPECT you might have fert buildup in the medium.
Water with a very weak veg fert with superthrive in it.
Keep it under 24/0 of intense light in the blue spectrum. I find flourescent to be perfect.
From now on, water lightly, and allow at least a month for the plant to revert to vegetative growth.
You should then be seeing some new shoots coming up from where you harvested. These can be taken for cuttings when they have about 4 nodes on them.