Webmaster Tools Crawler Errors 404

Fixing 1000 404 crawler errors in Webmaster Tools.

1.) Submitting URLs for de-indexing in Webmaster tools.

2.) On Wordpress platform, 301 redirecting the same URL using already installed plugin.

About half the errors will likely just have to redirect to the homepage as the content was deleted between November-January and does not exist anymore.

The other half still exists and you will need to cross reference all the URL from webmaster tools to the current posts to find the ones that still exist (using the slug) This happened because the old theme had the posts slugs with the date archive in them. When I changed the theme, it automatically switched the post slugs to just the post name. This is important as there is 600 posts on the website and I want the content properly linking.

3.) Once both of the above is complete, mark the crawler error as fixed in Webmaster Tools.