How Long Exactly Can I Wait to Replace a Ruptured Implant?

Replace within a month of discovery. The shell of the implant can erode through the skin causing a much worse issue than just the rupture.

From MIAMI DR. B

Although there is no urgency to removal/replacement of the ruptured saline breast implant, waiting for a prolonged period of time may lead to additional work necessary during the procedure to “reopen” the breast implant pocket, that tends to contract down over the deflated saline implant. Therefore, probably best to have the procedure done within a month of deflation, if possible. The advice above is quite general; you will do best seeking consultation with well experienced board-certified plastic surgeons in your area. Best wishes.

This depends on whether the implants are silicone or saline and what your plans are for the replacement (larger, smaller, lifted, profile change, etc?)