In order to do labour-intensive editing and proofreading tasks quickly, if you're using Word then you really need some programs called "macros".
Word has its own built-in programming language called Visual Basic for Applications (VBA), and a macro is a program created for VBA.
An example of a mundane but important task might be to search for all the examples of words ending in ize and ise and make them all the same.
Fortunately, someone called Paul Beverley has put together over 500 Word macros that carry out tasks like that. And it's free!
It's easy enough to integrate the macros with the basic template in Word (known as the Normal template), and full instructions are given.
There is copious documentation, but I have to tell you it is not the faint-hearted -- mainly because of its volume rather than its complexity.
Although the macros are in a book called Computer Tools for Editors, it includes useful tools for proofreaders too.
Download it from here: Computer Tools for Editors.