You can cut the carbon out or stuff the floss behind the cartridge for at least a month to get it started then remove the carbon cartridge. Don't just take out and replace, or you will crash your cycle.
Yeah do one at a time and put the cloth from it in the filter for about a month also. Then take the other out and do the same with your floss. You do not want to do it too fast or it will mini cycle. Your cycle is still too new to do it any faster, so be patient.