Step 1: Install the Administration Menu Module
First, let's download the module from drupal.org:
Go to http://drupal.org/project/admin_menu and download the Administration menu module.
In the admin area click "Modules" then the "Install new module" link to install the module.
Browse your file system and choose the file you just downloaded, then click Install. (In Google Chrome it says "Choose File" your browser may have a "Browse" button.)
Go back to the "Modules" page and scroll down to find the Administration section. Enable the module by clicking the check boxes.
Step 2 - Disable the Toolbar Module
Then scroll up on the page and find the "Toolbar" module. Clear the checkbox to disable the standard Toolbar. Clearing the checkbox for the standard Toolbar module avoids any conflicts caused by having two menus enabled.
When you are logged in you should now see the new menu, with expanded drop-downs and more direct navigation