All the new Office file formats (post Office 2007) are XML based — and can easily be opened and edited in an XML editing program. We already showed you how all these files are a bunch of XML files contained in a ZIP file container within our Theme XML Files tutorial. Although it is easy to unzip the files and edit some code in a basic program like Notepad, you will need a better program that does not require you to unzip and edit all the time, and then zip it up again! Thankfully there are plenty of programs that allow you to edit these Office XML files — our favorite is Microsoft’s own Visual Studio. On its own, Visual Studio cannot open and edit Office XML files — but Microsoft provides a free add-in that plugs into Visual Studio and lets you edit the Office XML files.
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