Split and merge PDF documents in C# and VB.NET
Split and combine PDF
Docotic.Pdf library can be used to split and merge PDF documents in .NET. Look at the following articles for more detail:
Add, remove, or reorder PDF pages
You can add new pages to PDF documents or remove existing ones with the help of the library.
Take a look at samples that show how to add new pages and insert or remove existing PDF pages.
You can also change order of pages in your PDF documents.