SEO - How to properly remove an outdated page?

Question

Search Engine Optimization

There is a static site located on GitHub Pages, on the third level domain *.github.io
This site is indexed by search engines and has a certain traffic. The site has sitemap.xml and robots.txt.
One obsolete page needs to be removed. It is correct to use 301 redirects for this, i.e. send the appropriate header. If some server was used, Apache for example, then this is easy to do, but how to do it on GitHub Pages.
Questions:

1. Is it possible to make some kind of 301 redirect on a static site hosted on GitHub Pages?
   
2. What changes need to be made to sitemap.xml and robots.txt when deleting a page from a site?
   

Answer 1

404
or 410 - if absolutely forever
301 - if there are good backlinks, otherwise give 404

Answer 2

Just remove the page let it return 404

Answer 3

It's like no. Is it possible to write down on js
but in general, if the page is no more, then you need to give 404)))

Answer 4

https://stackoverflow.com/a/19717455/890863
301 will not work, but Google Bot understands as 301 redirect. For jekyll on github-pages, this can be conveniently done using the jekyll-redirect-from plugin: https://help.github.com/articles/redirects-on-gith...