I'm trying to update drupal core on a large multisite version of drupal. He only wants core updating for a security update. However, I can't see any instructions out there on just updating core without updating all the modules, unless you have drush installed. (I tried updating all of them anyway on my dev box and the update failed because of duplicate entries in the nodewords table).
He doesn't have drush and I don't have the ability to add it. Is it possible without drush?