Harvest and cutting

So basically I am wondering how to go about cutting the top cola/buds off my plant and allow the bottm half to continue maturing. Do I cut the main stem? This seems the most logical, but won't that hurt the plant and the rest of the budding? Sorry for the silly questions, It is my first time harvesting, I still have a about 2 or 3 weeks to go but I want to be prepared. When I do this cut any particular method or just razor blade slash cut?

Peace.

just cut it right at the stem and enjoy that baby

Cool, I will chop her when she's ready. Thanks.