Changing permalinks structure without loosing SEO

You don’t need a plugin to achieve your goal. Use server redirect in the .htaccess file because it will not load the processor to interpret the WordPress PHP code and will not consume time. The redirect will be completed before the WordPress runs.

RewriteRule ^[0-9]+/[0-9]+/(.*)\.html$ /$1 [R=301,L]

Where

  • [0-9]+/ is the numeric year and month
  • (.*) is the part we’ll use below (example-post in your case)
  • /$1 is the part we’ve got from the above

301 redirect is completely perfect for SEO.