Just cut it to about 1/2 the height u want them to fnish. U gotta keep In mind most will double in size for the flower stretch. I personally would top it, fim the new tops that come out and tie it all down so u endp up with a 4ft tall 6ft round bush with like 12 donkey dicklike colas pokin their head out. Not sure where ur at though. If ur starting flower or if its sexing around now I would just lst don't wanna chop off the cola if there's no time for a new one to takes its place