The developers of this application don't exist anymore. I have tried finding a way to contact them, but it's impossible. Without a website and relevant information, it's hard to say what the correct process is when it comes to upgrading, or if it's even available. If you have the software, go to Help > About and use the available information to get in touch with them. There should be a phone number or a contact email address available. There is no other way around this.