- add a redirect so the link goes to the homepage
- add the page back to my website with some content that sort of fits.
Changing the backlink is unfortunately not an option.
Bridge content can be helpful. It serves the needs of people looking for something specific while introducing them to the rest of your site.
An example of bridge content is like an article on a bicycle Website that talks about shoes, and a shoe Website links to the article. So people who are interested in shoes may be looking for good bicycle shoes and your bicycle shoes article mentions some of the bicycles you review/sell on the rest of your site (linking to them).