Search the marketplace for "Tealium", then click the Tealium Tag Management extension.
Click Install Now
Check the the Extension license terms box to agree to the terms then click Get Extension Key
The Extension Key will appear in the key field. Copy the Extension Key.
Navigate to the Magento Admin Panel and select System > Magento Connect > Magento Connect Manager.
Under Install New Extensions, paste the Extension key you copied from the Magento Extension marketplace into the empty field and click Install.
Under Extension dependencies click Proceed
Wait for the following message to appear beneath the console, "Procedure completed. Please check the output frame for useful information and refresh the page to see the changes.", then click Return to Admin.
Next, from the Magento Admin Panel, select System > Configuration
In the left-side navigation, under the Tealium heading, click Tag Management
Update the config settings with your account information: