Updating WordPress Core on a plugin

Why would a plugin want to update WordPress core?

i am writing a plugin that creates a custom xmlrpc methods and one of my tasks is to update the wordpress core of multiple sites in one remote application…

Have you had a look at wp-admin/upgrade.php and wp-admin/upgrade-functions.php?

Yeah.. but i have no idea on how to use it… im just new into plugin development..

Have you reviewed Writing_a_Plugin?

yes…