Simsi - 11:23 pm on Nov 15, 2012 (gmt 0)
One thing I did a couple of times was to write a fresh page and link from the ranking one with something like "an updated version of this article is available here". The new page never outranked the old one despite being better but at least it gave users a more accurate option.
FYI I "tweaked" some text on the original pages simply to ensure the info wasn't so out-of-date it was useless. Had no effect on ranking. I've since become a little bolder and changed ranking content but never more than a paragraph or so at one time (yet!).