KDP Book Trim Resize

I need to move fast on a KDP interior that is currently laid out at 8.5 × 11 inches. The file is digital only, so you will be working directly on the source layout and returning a press-ready PDF plus the updated working file. My goal is to reduce the trim to one of Amazon’s standard smaller sizes—6 × 9 is my first choice, but I will consider 5 × 8 or A5 if you think one of those will preserve the design more cleanly. Page count, page numbers, images, headers, and bleed must stay perfectly aligned with KDP’s print specifications after the change. Please confirm which software you will use (InDesign, Affinity Publisher, or another tool able to meet KDP requirements) and how quickly you can turn this around. Deliverables: the resized, print-ready PDF that passes KDP’s previewer and the editable source file.

Project ID: 40175790