How to Redirect Permanent to new Blog

I was reading this post – https://ma.tt/2008/01/on-matt/ and was interested to know how did matt redirect his old blog and all the inner pages interlinked within the blog posts so quickly? Did he do the job manually or can anyone link me to any source which can explain this job please. I wanted to redirect the whole blog and stuff from https://www.currentwebsite.com/blog/ to another https://www.newblog.com/ please email me with some steps regarding the same.