Combine multiple Word documents into one and reformat

I had someone write a Safety Manual for me a few years ago. He returned about 50 Word and Excel files which we were supposed to print out in order, and he didn't do a very good job of using Word Styles or formatting. I would prefer everything to be put into a single Word document, with correct Styles (Heading 1, Heading 2, etc) and properly formatted bullet- and numbered- lists. I want to be able to make changes to that one document and then update the Table of Contents and reprint the entire Safety Manual. I will provide the 50-60 files, and last year's version of the complete manual in PDF format. You would amalgamate all files into one, and then apply correct heading styles to every heading and subheading. You would also make sure all numbered and bullet point lists are consistently formatted. This needs to get done by Thursday, January 4th.