Suppose an old closed question has an historical lock on it, making impossible to vote/comment/flag on any post.

What should we do if such questions have a high visibility but contain outdated or wrong information?

For instance

What are best practices that you use when writing Objective-C and Cocoa?

provides a lot of useful information and currently has 86154 views, however the information contained in the answers are starting to become outdated as the language and the framework evolve over time. Right now most of the suggestions are still applicable, but the situation can only get worse.

The question specifically is the first result on Google for the query "cocoa best practices" and the third for "objective-c best practices"

I would normally comment, suggest an edit or post an other answer, but the lock prevents me from doing that.

Are such questions destined to keep being hit by searches and to provide outdated information forever?

EDIT

The question was closed as duplicate of http://meta.stackoverflow.com/questions/156219/what-if-the-answers-of-a-historical-locked-question-become-obsolete#156226, however I don't believe the accepted answers fully answers the problem.

In the example proposed, for instance, I think the post still deserves an historical lock as the information provided is indeed useful. Only little parts of it are gradually becoming outdated and still being hit every time one queries for cocoa best practices.

What to do when an historical-locked question provides, say 85% of useful up-to-date information and 15% of outdated one?