Download and untargz the pathauto (plus dependency token module)
Enable those modules
Modify the default patterns (back and forth to get rid of the errors)
admin/config/search/path/patterns
examples: DEFAULT CONTENT PATH PATTERN = content/[node:title] DEFAULT TAXONOMY TERM PATH PATTERN = category/[term:name] DEFAULT USER PATH PATTERN = users/[user:name]
If necessary, go back to the Content Listing admin/content?page=1 and modify old stories that need the URL Path Settings at the bottom to have the checkbox checked "Generate automatic URL alias"
You may also want to fix old Taxonomy categories: admin/structure/taxonomy/vocabulary_1 (edit)