The patch was created with Tortoise SVN.
I recommend installing Tortoise SVN and create a local repository.
Import PdfSharp to your repository and then check it out, so the files are versioned.
In the directory, where you have checked-out PdfSharp, navigate to the Folder where you find the Solution file. (*.sln)
Right-click in Windows Explorer, go to the "Tortoise SVN" Menu and select "Apply patch".
Select the attached patch file.
https://tortoisesvn.net/docs/release/To ... patch.htmlFor further information, please consult the Tortoise SVN Documentation.