Delphi XE2 TZipFile: replace a file in zip archive

I'd like to replace a file (= delete old and add new) in a zip archive with the Delphi XE2/XE3 standard System.Zip unit. But there are no replace/delete methods. Does anybody have an idea how it could be achieved without needing to extract all files and add them to a new archive?

I have this code, but it adds the "document.txt" once more if it's already present:

var
  ZipFile: TZipFile;
  SS: TStringStream;
const
  ZipDocument = 'E:\document.zip';
begin
  ZipFile := TZipFile.Create; //Zipfile: TZipFile
  SS := TStringStream.Create('hello');
  try
    if FileExists(ZipDocument) then
      ZipFile.Open(ZipDocument, zmReadWrite)
    else
      ZipFile.Open(ZipDocument, zmWrite);

    ZipFile.Add(SS, 'document.txt');

    ZipFile.Close;
  finally
    SS.Free;
    ZipFile.Free;
  end;
end;

Note: I used TPAbbrevia before (that did the job), but I'd like to use Delphi's Zip unit now. So please do not answer something like "use another library". Thank you.