Update a Microsoft Outlook Form

25 years ago I built a form for my client using Outlook. Now I have to change some text, add some controls. I don't support Outlook any more, so if anyone wants to do the work, I would be grateful. A minor inconvenience is that the text is in French. That should not be a problem as you can just copy paste our news content.

Also, my client is selling this form, so we need to know how to install his form on his own clients Outlook.