When you go to web content in control panel, there is no subscribe button for subscribing purpose.
You can subscribe to web content in control panel clicking in the drop down menu in "Home" (in the left side panel), you can see the attachment.
PASSED Manual Testing following the steps in the description.
Tomcat 7.0 + MySQL 5. Portal 6.2.x GIT ID: 6d9001e0e1f78a4b87bc5df4c470c5f8909a8618.
When clicking in the drop down menu in "Home", I can see subscribe.