The method is about use xenu to get into the directories to find out dead blogs. after that, use the wayback machine to get all the content of the dead blogs.
Just because the blog is “dead” (whatever that means), it doesn’t mean the content is available for you to copy into your own blog. It will still be someone’s copyright, and you will be infringing that copyright if you use it without permission.
We see a lot of questions here in the forum about how to acquire content for a blog or website. Ultimately, if you can’t create content yourself through you own skill and industry, and you don’t want to pay other people to create it for you, I have to wonder why you would want to run a blog in the first place.
Generally the blog content will still be covered by copyright unless the author died at least 50 years ago (in many countries 70 years).
So you would need to be looking for blogs abandoned before 1944 and then check that the author actually died by 1944 to be certain that the content of that blog is allowed to be used.