Book cover and back art

We have the mock-up already done. The book is already for sale on Amazon through KDP. We have decided to change the title of the book, and a few minor changes on the cover, and a one-sentence replaced change on the back cover. Feel like this would be a very simple job. Able to include the actual file with original cover from graphic designer that I usually use (he is unavailable for the next 6 weeks, and I would like this to be completed by 12/18/22 at the latest.