Google give us the option to Demote a sitelink URL within Webmaster Tools. According to the help page:
Once you've demoted or undemoted a sitelink, it can take some time for search results to reflect your changes.
Is there any indication on just how long it will take? Is there any notification when it's actually been processed?
When I have demoted site links, it has taken less than 24 hours for them to disappear from the search results.
I have never gotten a notification that it was successful. The demotions I've put in are still listed in Google Webmaster Tools years later.
It looks like they expire eventually. One of the ones I put in first now says that it will expire in May 2015.
