Because there are many possible scenarios, it will be simpler to accomplish this if you contact Technical Support and provide certain essential pieces of information that will allow Technical Support to advise you on the simplest approach for your particular situation.
Please go to www.gradiencesupport.com and click on Submit a Request and explain in the body of the request that you are moving away from Optima or MyBiz and toward Gradience.
Please tell us...
1. Whether you plan on running it on a server & clients or just one computer.
2. The operating system(s) of the computer(s) on which you intend to install version 12.
3. Whether you plan on installing over the top of the old software or moving the software.