Presentation Design - Google Slides

We have recently had our Media Pack redesigned. We are now looking to roll out the design onto other supporting sales documents.
The first is our proposal document. 80% of the design has been transferred but it needs finalising and one of the pages needs more attention to bring it in line with the new design.
This is a 9 page document and is in Google Slides.
I'd like someone to spend 2 hours max carrying this out.