I've tried many ways to use a new JSF version, even used Maven but I could not success.
If using Maven, you will get a new library version (you see at project files & library). When complying and running at Netbeans console, it still shows the old version, because the Netbeans refers a library to Glassish server (if using Glassish server).
Another way I ever tried by adding the new JSF library at Ant Library Manager, it still uses the old version.
Solution if you are using Glassish server:
1. Go to /Applications/Netbeans/glassfish-4.0/glassfish/modules/2. Replace the javax.faces.jar with javax.faces-2.2.6.jar
3. Restart Netbeans
4. Clean and build your project
5. You will see at Netbeans console, like this:
Info: Initializing Mojarra 2.2.6 ( 20140304-1537 https://svn.java.net/svn/mojarra~svn/tags/2.2.6@12949) for context '/myApplication'
Noted:
1. I don't know why when updating a new library with Netbeans, it could not work, for example JSF.
2. Once you finished updating JSF version, you will see JSF 2.2 (when creating new web application.