Providing the site publishing Feature is activated, you can change a site’s master page via the Web interface.
The publishing Feature must be activated on a site before you can access the site’s Site Master Page Settings page and change the master page. This option is only available on SharePoint Server 2010 sites. See the “SharePoint Foundation 2010 Sites and Master Pages” section later in this chapter for details on how to change the master page in SharePoint Foundation 2010 sites.
You can access and change a site’s master page by accessing a publishing site’s Site Settings page and clicking Master Page (see Figure 6.60).