If you've purchased additional social profiles, team members, hashtags, competitors or feeds and you no longer need these but don't want to cancel your current plan, go to the Subscription section.
There you'll see your add-ons listed with the features of your main plan:
Click 'Edit add-ons' at the bottom to go to this screen:
and then click on 'Cancel extra competitors/hashtags/team members', as applicable. These will remain active until your plan's next renewal date but will not renew along with your main plan.