what is the common academic way of linking a section of a paper to a previously published paper? Assume you have a published paper in journal X. Now, you are writing a manuscript for journal Y. One section of this manuscript is very similar to what you published in X. 
So how is the common academic way of referencing this section to that published paper?
I mean, it would probably look like this:

III. Method blah blah

This method has been previously addressed in this paper [ref].
The point of writing a scientific paper is to communicate what you have done and how. A key factor is to keep a clear trail of your sources. If you need to re-iterate an already published method you basically have two options:


Simply state that you use the method described in "so and so" (yyyy). If you have made any changes to the method originally described you do of course need to provide details on those changes.
If the method is somehow so key to your paper that you think it is worth re-iterating the method description then rewrite it in your own words and, perhaps, start out by saying. I have followed the method described in "so and so" (yyyy), what follows is a re-iteration of his/her/their description. You can of course include changes you have made to the method but then it has to be crystal clear to the reader what is from the older paper and what is new.


It is quite common, at least in some fields, to provide a abbreviated description, focussing on key aspects and ignoring parts that are more obvious. After all the reference to the original description should be given and the source for the information is there. 

What you should totally avoid is to quote the section from the older paper. It is always better to provide your own version of whatever you are "quoting", since this may make clear your interpretation of what was originally said. Straight quotes hide such effects.