I know its possible - Follow a person? using RSS
How do I do it? I don't see any link in user profile.
Check the page, it is there:
<link rel="alternate" type="application/atom+xml" title="Feed for user 01" href="/feeds/user/136179">
that's the 23rd line from the top of the document, linking to the relevant RSS feed. There's a normal link at the bottom of the page (like everything else on SO that has a RSS feed). See the screenshot.