They're pretty resilient shrubs, hence the conflict about pruning! Don't do it now, though, you may force new growth which you really don't want as winter is so close. You can either do it when the plant is dormant, over winter, or in Spring. If you want to do it twice next year, do it again in June or July. This plant is used as hedging sometimes, when it gets cut 2 or 3 times a year.