internal links

Hi I am new here and hoping to find an answer to redirects please. My to nav bar has a link to e.g business. co. uk/ pageold I changed the link to business co.uk/ pagenew I used a redirection to do this. Now AHREf shows that this link needs to be linked to the destination page I redirected it because I have added the original link business.co. uk /pageold to social media and so when someone clicks it they should get the updated business.co.uk / pagenew

I don't know how to change just the internal link on each of the landing pages on the website without losing the originl link.