Put the new package tarball to:
<username>@frs.sourceforge.net:/home/frs/project/octave/Octave\ Forge\ Packages/Individual\ Package\ Releases/

It will take some minutes until the tarball is automatically copied
from there to be available online.

unpack the package html and do something corresponding to:

rsync -av --delete <package-name>-html/<package-name>/ <username>,octave@web.sourceforge.net:htdocs/packages/<package-name>/

update <username>,octave@web.sourceforge.net:htdocs/news.html

remember to notify the package maintainer at the release forum, the
maintainer should announce the release at the list

tag the release changeset in the repository (only for 'community'
packages)

hints:

htdocs/ (see above) at the web-site corresponds to htdocs/ in the
'project-web' package, but contains some more directories (in
particular, under htdocs/packages/, the html directories of the
individual packages), some generated files, and maybe some more
files. Note that htdocs/news.html is not necessarily always in sync
between the web-site and the 'project-web' package (the file at the
web-page being potentially newer; this is to avoid too frequent
commits to the project-web package).

I'm using a local copy of the web-site, serviced by apache2 for
localhost, and do any changes there first, before I propagate them to
the real web-site. Before I propagate the package html to Octave
Forge, I check from the local copy whether the package tarball is
already available for download.