Updating the SharePoint Default Master Page

1. Find the default master page located in the Master Page Gallery. In Office SharePoint Designer 2007, the Master Page Gallery is the masterpage folder, which is located in the _catalogs folder in the Folder List.
2. Create a copy of Default.master rather than modifying Default.master directly. However, if you do make changes directly to Default.master and are not satisfied with the changes that you have made, you can always reset Default.master to the site definition
3. Create a copy of Default.master:
In the Folder List, right-click Default.master, and then click Copy.
Right-click the masterpage folder, and then click Paste.
4. A new master page named default_copy(1).master appears. You can now modify and then rename this page.
5. Make changes to the master page.
Note If you are not satisfied with the changes that you have made to the master page, you can always reset it to the site definition. By right clicking on the masterpage in SharePoint Designer and making the selection.
6. After you create the new master page, you can make it the default master page for the entire site. In the masterpage folder, right-click the page that you want to use as the new default master, and then click Set as Default Master Page on the shortcut menu.
Note If the master page is already the default master page for the site, the Set as Default Master Page command is unavailable.
7. When you set a new master page as the default master page, all of the pages that are attached to the current version of Default.master, including the pages that already exist in your site as well as any new pages that you create that are attached to Default.master, will be attached to the new master page.
8. Navigate to the site settings page
9. Select the Master page gallery from the list of options.
10. Navigate down the list of master pages and page layouts in the gallery to the master page that has been updated.
11. Choose the drop down arrow next to the page and select "Publish" from the drop down menu.
12. Choose the drop down arrow next to the page and select "Approve" from the drop down menu.
13. The status of the page should now have changed from "Draft" to "Approved".