using GroupDocs.Metadata;
using GroupDocs.Metadata.Common;
using GroupDocs.Metadata.Tagging;

namespace  RemoveMetadatafromPPTUsingCSharp
{
    internal class Program
    {
        static void Main(string[] args)
        {
            // Set License to avoid the limitations of Metadata library
            License lic = new License();
            lic.SetLicense(@"GroupDocs.Metadata.lic");

            using (Metadata metadata = new Metadata("input.ppt"))
            {
                // Remove all the properties satisfying the predicate:
                // property contains the name of the document author OR
                // it refers to the last editor OR
                // the property value is a string that contains the substring "John" 
                // (to remove any mentions of John from the detected metadata)
                var affected = metadata.RemoveProperties(
                        p => p.Tags.Contains(Tags.Person.Creator) ||
                        p.Tags.Contains(Tags.Person.Editor) ||
                        p.Value.Type == MetadataPropertyType.String 
                        && p.Value.ToString().Contains("John"));

                Console.WriteLine("Properties removed: {0}", affected);

                metadata.Save("output.ppt");
            }
        }
    }
}