You know there is a sub-forum that specifically deals with harvesting?
Cut off the upper 2/3 of the plant, put into 24/0 light cycle, flush then re-start with veg nutrients.
Most growers don't re-gen. Here's why:
First, it's a huge stress factor on the plant to have the top 2/3 cut off and put back in a veg cycle.
It takes 2--4 weeks to make the switch. Some plants die from the shock; others go into a kind of "suspended animation" type deal.
If they make it, then you need at least a month for the plant to grow more branches.
Then, when you re-flower, yields are usually meager.
You'd get MORE bud if you planted new seeds and grew new plants.