// PM> Install-Package IronPdf
using IronPdf;
// Create a new PDF or edit an existing document.
using PdfDocument Pdf = PdfDocument.FromFile("existing.pdf");
// Add a bookmark
Pdf.BookMarks.AddBookMarkAtEnd("Summary", 17);
// Add a sub-bookmark within the summary
Pdf.BookMarks.AddBookMarkAtEnd("Conclusion", 17);
// Delete an old Bookmark
Pdf.BookMarks.RemoveBookMarkAt(0);
Pdf.SaveAs("existing.pdf");
' PM> Install-Package IronPdf
Imports IronPdf
' Create a new PDF or edit an existing document.
Private PdfDocument As using
' Add a bookmark
Pdf.BookMarks.AddBookMarkAtEnd("Summary", 17)
' Add a sub-bookmark within the summary
Pdf.BookMarks.AddBookMarkAtEnd("Conclusion", 17)
' Delete an old Bookmark
Pdf.BookMarks.RemoveBookMarkAt(0)
Pdf.SaveAs("existing.pdf")