To perform a word count in PDF or WinEdt, users can utilize the tool Texcount, which analyzes TeX files and provides detailed statistics, including word counts in text, headers, float captions, and math elements. While the accuracy of Texcount's results is not guaranteed, it offers a comprehensive breakdown of the document's content. Users need to run a Perl script to use Texcount, and ActivePerl is a recommended option for Windows users. The tool has been reported to work effectively for those who have tried it.