How difficult it is to downsize breast implants by 200cc with pocket tightening?

Dear user162626,
generally speaking, you will need to get another surgery in order to reduce the size of your implants and pockets. If you are considering surgery, I would suggest you consult a board-certified plastic surgeon. Only after a thorough examination, you will get more information and recommendations.
Daniel Barrett, MDCertified, American Board of Plastic SurgeryMember, American Society of Plastic SurgeryMember, American Society of Aesthetic Plastic Surgery

Because the pocket was stretched anteriorly as well as laterally, most women do fairly well going down about 150 cc's and tightening the lateral pockets. Usually it is less painful, but you still need the same amount of time to recover. If you use the same surgeon, you might get a discount for the surgical cost. However, the cost for the surgery center fee, anesthesia, and new implants will not be adjusted or reduced.