Hi, Upnorth.
To my understanding, the amount of CBD, THC or other cannabinoids a plant produces is genetically determined. If you are growing a high CBD strain it should automatically do so.
Pistil color and trichome color are key indicators of when to harvest. From the pistil pictures, your buds are still immature. Go back to the GWE main site. They have a TON of info and pics on how to time your harvest.