// Install IronPdf with Nuget: PM> Install-Package IronPdf
using IronPdf;
// create a new PDF or edit an existing document.
PdfDocument Pdf = PdfDocument.FromFile("existing.pdf");
// Add a bookmark
Pdf.BookMarks.AddBookMarkAtEnd("Summary",17,0);
// Add a sub-bookmark within the summary
Pdf.BookMarks.AddBookMarkAtEnd("Conclusion",17,1);
//delete an old Bookmark
Pdf.BookMarks.RemoveBookMarkAt(0);
Pdf.SaveAs("existing.pdf");
' Install IronPdf with Nuget: PM> Install-Package IronPdf
Imports IronPdf
' create a new PDF or edit an existing document.
Private Pdf As PdfDocument = PdfDocument.FromFile("existing.pdf")
' Add a bookmark
Pdf.BookMarks.AddBookMarkAtEnd("Summary",17,0)
' Add a sub-bookmark within the summary
Pdf.BookMarks.AddBookMarkAtEnd("Conclusion",17,1)
'delete an old Bookmark
Pdf.BookMarks.RemoveBookMarkAt(0)
Pdf.SaveAs("existing.pdf")