According to the FAQ,
I already entered my experience and education on LinkedIn.
Great! You can import it from LinkedIn with just three clicks.
Unfortunately, it doesn't say which 3 clicks, and I wasn't able to find them.
Does your sidebar look like this?
If you are not an active candidate, you may not see the link to edit your profile, which is the only page that shows the LinkedIn import link. If you are a passive candidate or you have no profile at all on Careers, you will need to obtain an invite in order to create a profile and import your LinkedIn information.