Q: Changing "tokens" in .xlsx document with SpreadsheetDocument from OpenXml During validation process xlsx document is converted to pdf. 
Inside of this xlsx documents there are "tokens" which need to be override with proper values.
To do this I'm using this:
 byte[] fileContent = document.Contents;
    using (MemoryStream mem = new MemoryStream())
    {  
        mem.Write(fileContent, 0, (int)fileContent.Length);
        OverrideXLSX(mem, document);
    }          


    private static byte[] OverrideXLSX(MemoryStream mem, Document document)
    {
        byte[] toReturn;
        using(SpreadsheetDocument sprDoc = SpreadsheetDocument.Open(mem, true))
        {                      
            foreach(WorksheetPart worksheetPart in sprDoc.WorkbookPart.WorksheetParts)
            {               
                OverridXmlPart(worksheetPart, document);            
            }       
            mem.Position = 0;
            toReturn = mem.ToArray();
        }
        return toReturn;
    }

    private static void OverridXmlPart(OpenXmlPart xmlPart, Document document)
    {
        foreach (IdPartPair part in xmlPart.Parts)
            OverridXmlPart(part.OpenXmlPart, document); 

        string docText = string.Empty;
        using(StreamReader sr = new StreamReader(xmlPart.GetStream()))
            docText = sr.ReadToEnd();

        if (docText.StartsWith("<?xml ") && docText.IndexOf("token_", StringComparison.InvariantCultureIgnoreCase) > 0)
        {
            docText = OverrideTokens(docText, document); //This is chaning the tokens to the right one in thext
            using (StreamWriter sw = new StreamWriter(xmlPart.GetStream(FileMode.Create)))
                sw.Write(docText);
        }
    }



 private string OverrideTokens(string docText, Document document)
    { 
       return docText.Replace("token_id", document.Id); 
    }

But this is changing only some of the tokens. Looks like I'm not searching in all of the places. Can someone point me what I'm doing wrong in here?
Here is example of the xlsx before changing tokens, and generated pdf:
https://1drv.ms/f/s!AiO9pakkDfFygaI57tLcxWBC3q68IA
Here is the answer: open xml excel Insert actual value in the placeholder
