The Extended Live Archive plugin is one selfcontained bundle called af-extended-live-archive, which should be put into the plugin folder to yield the following structure:
wp-content/ \_... \_ plugins/ \_... \_ af-extended-live-archive/ \_ elalicenses.txt \_ af-extended-live-archive.php \_ af-extended-live-archive-include.php \_ af-extended-live-archive-options.php \_ includes/ \_ af-extended-live-archive.js \_ af-ela.php \_ af-ela-style.css
The plugin writes some javascript information to the header of each page, and provides a single template function called af_ela_super_archive().
However, it is STRONGLY recommended that one uses the option panel the plugin is adding to the admin pages to configure ELA.
Doing so, all one has to do to display the Extended Live Archive is to add a <?php af_ela_super_archive(); ?> call wherever one wants to stuff to show up.
Note that if you are using K2 beta one r96+, the archives page is already doing that for you.
To install the plugin, upload the af-extended-archive directory and its content to your wp-content/plugins/ directory. Then, visit the option->Ext. Live Archive page once to initialize it.
The plugin HomePage can be found somewhere in SonsOfSkadi.net and the support forum is over at Flickr.