Locking Microsoft Word headers, footers or other content

Some existing references, which using header protection through sections and edit restrictions
https://answers.microsoft.com/en-us/msoffice/forum/msoffice_word-mso_windows8/im-trying-to-lock-the-header-and-footer-on-a-word/1c0d34b3-bdb1-4a93-9969-181c8e198785
https://wordribbon.tips.net/T011567_Protecting_Headers_and_Footers.html

Different approach for locking data for editing since Word 2010
The simplier and more flexible way to restrict editing of headers, footers in Microsoft Word document is to use Richtext Content Control (https://msdn.microsoft.com/en-us/library/bb157891.aspx). To lock the header or footer (any other blocks could be used) from editing, deleting you could select content required to be locked and click on RichText content control in Developer ribbon. As a result your selection will be enclosed in RichText content control and you will be able to set properties whose disables editing and deleting of selected content.