I am interested to find out how someone can gain access to a Search Console account when a staff member has left.

JOHN MEULLER (Webmaster Analyst from Google):

So, essentially, for a Search Console,you can just verify the site again.You don’t need to do anything special.It’s a bit different with Search Console than with Analytics,for example, in that in Search Console you don’t lose any data if one account is closed and another one is open.So you don’t need to gain access to the previous account– you could just verify it again.And then a question if anyone has implemented React– I don’t know.I haven’t looked at the link, but it says SEO in the URL,so maybe it’s good.