Editing master pages on the server from Visual Studio

You can edit a master page that is in a website template directly from Visual Studio.
To do this, perform the following:

Open Sitefinity Explorer.
Select Website Templates » <TemplateName> » Master Pages » <MasterPageName>.
Double-click the master page that you want to edit and wait for Visual Studio to download and open it.
After you finish editing the master page, press CTRL+S.
It is automatically uploaded back to the server.