How to edit content of aspx SharePoint page programmatically?

Question

There are so many page layouts with same content inside. I need to remove some of the content from these pages through c#. For example page layouts contain:

<%@ Register tagprefix="xyz" namespace="abcd" assembly =abcd, version= 16.0.0.0, publickeytoken =713567888>

I need to remove this content from all the page layouts. Manually editing each and every page layout is very difficult. As I am not a techie , could you please help me here?

Answer 1

I think you are trying to edit the Master Pages of the SharePoint sites. You can view the Master Page from

http://Sharepoint_Site_Name/_layouts/15/DesignMasterPages.aspx

You can also view them from the SharePoint Designer by opening a site and opening the "Master Pages" menu from the left hand side.