This blog is showing each and every steps which are needed to add those codes into the WordPress Website or Blog.
Step 1: Go to your WordPress login page and type your “Username” and “Password” to login.
Step 2: Go to Plugins area.
Step 3: Click on “Add New” button from top side of the plugins page.
Step 4: Search a plugin named Header and Footer Script.
Step 5: Click on install button to install that plugin and after that activate it.
Step 6: Now go to settings -> Header and Footer Script.
Step 8: Click on Save Settings.
These Steps are also present in Video.