first, WHY do you want to prune it at all ? ... usually, the only reason to 'top' the plant, is to force it to shorter height, and you will get two shoots to bud, instead of the single ... some favor pruning, some don't ... if you have the room for it to stretch, don't top it at all, in fact, you may prefer to just tie the stem down instead ... if you do decide to top it, just cut off the growing tip ... simple enough ... just cut it a short distance above the crotch of the stems just below the tip ... you cant screw it up too easily, but don't get carried away ... some strains stress under pruning, and will turn male on ya ... I would let it grow taller, first ... let it go a foot or so, then decide if it wants to be topped ... hope that helps ... :smokin: