The silicone gel implants come pre-filled and therefore do not contain a port like the saline implants do. This being said, there is no way to remove contents of the implant without rupturing the implant. If you wish to downsize the implant they need to be removed and replaced with smaller cc silicone gel implants (should this be your choice). I suggest you set up a consultation with a board certified plastic surgeon to look into your surgical options.
I hope this helps you and good luck
Fadi Chahin MD, FACS
Plastic and Reconstructive Surgery
Diplomat, American Board of Surgery
Diplomat, American Board of Plastic Surgery