Edit a front and back cover for a children's book

I need a designer who specializes in creating and editing designs for a children's book . I have 2- front and back covers created and meed some edits - particularly resizing and adding die cut lines according to a template on to the design which has already been made. These will be passed on to my manufacturer so they need to be in the correct profesional format for my designer to then print the book. Preferably someone UK based.