With this free plugin, you can change almost everything: admin menu and pages, login page, admin bar, etc. Another very interesting option is that the plugin lets you apply admin panel themes, though most of them aren’t free and not especially beautiful, in my opinion.
Free download: Ag Custom Admin
Admin Menu Editor
If you need to customize a WordPress admin menu, then Admin menu editor is definitely a plugin to consider.
Article source: https://dzone.com/articles/best-wordpress-plugins-to-customize-the-admin-area