British English School Book Proofreader

I have a completed school book manuscript that just needs a careful, British-English proofread. The text is already typed and formatted; your task is limited to fixing any clear spelling, grammar and punctuation mistakes while preserving every sentence exactly as it is. Please work directly in the Word file, using Track Changes so I can review each correction, and then supply a clean, final version once everything is approved. No rewriting, rephrasing or stylistic edits are required—accuracy and consistency are the whole brief.