When you notice that a port is out of date compared to the latest version from the original authors, first make sure you have the latest port. You can find them in the ports/ports-current directory of the FTP mirror sites. You may also use CVSup to keep your whole ports collection up-to-date, as described in the Handbook.
The next step is to send a mail to the maintainer, if one is listed in the port's Makefile. That person may already be working on an upgrade, or have a reason to not upgrade the port right now (because of, for example, stability problems of the new version).
If the maintainer asks you to do the upgrade or there is not any such person to begin with, please make the upgrade and send the recursive diff (either unified or context diff is fine, but port committers appear to prefer unified diff more) of the new and old ports directories to us (e.g., if your modified port directory is called superedit and the original as in our tree is superedit.bak, then send us the result of diff -ruN superedit.bak superedit). Please examine the output to make sure all the changes make sense. The best way to send us the diff is by including it via send-pr(1) (category ports). Please mention any added or deleted files in the message, as they have to be explicitly specified to CVS when doing a commit. If the diff is more than about 20KB, please compress and uuencode it; otherwise, just include it in the PR as is.