For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.Pdf-for-C
auto ce = MakeObject<Facades::PdfContentEditor>();
ce->BindPdf(L"..\\Data\\Text\\input.pdf");

auto options = MakeObject<TextOptions::TextReplaceOptions>(TextOptions::TextReplaceOptions::Scope::REPLACE_FIRST);
ce->set_TextReplaceOptions(options);
ce->ReplaceText(L"example", L"file");

ce->Save(L"..\\Data\\Text\\input_out.pdf");