No specific action is required.  Old questions don't need closing simply because they are old and/or outdated. 


All posts are dated and people sufficiently literate to use a search engine to find an older Q&A should be capable of reading the date that accompanies every post even when a specific release/version number is omitted. 

Also people may even be searching specifically for old information because they're dealing with a legacy system. 


Questions that get no love get deleted automatically by [the system](http://meta.stackexchange.com/q/5221/282031) after a certain expiration time.  
That fact that that hasn't happened is one indication that at least at the time the question was posted it was considered a suitable post. 

Questions older than 30 days can't be migrated, but if by current standards it is no longer a suitable post, then one the other existing pre-defined close reasons can be used and should suffice.  
You can also still down vote the question (which may result in the question getting re-evaluated by [the system](http://meta.stackexchange.com/q/5221/282031)  triggering automatic deletion).