Steps: Open SharePoint Designer 2013 with Source Site collection URL. Click on master page under site objects on the left side just below to the Navigation Select the Master.html file and click on Export File from ribbon and Open SharePoint designer 2013 with Our new Destination site collection URL. Click on master page under site objects on the left side just below to the Navigation Click on Import file from the ribbon it will open a popup Click on Add file… select the Master.html file from the desktop location Click on Open and then click OK Button Now the Master.html file is uploaded Form SharePoint Designer 2013 Right click on the Master.html file and click on check out Form SharePoint Designer 2013 Right click on the Master.html file Edit file in Advance mode Make all necessary changes in the Mastre.html file and click on Save icon...