open the intall folder for the year you're looking to transfer (ie proseries 17). This is usually on our c: drive, but depending on your installation choice, it could be a different drive.   You should see ProWin17.
 Open that folder and copy the folder that says "17data" to a flash drive.  Then on your new computer, simply paste that data into ProSeries17 folder with the same name (17data).  Be sure to have ALL THE forms, state returns, etc already installed on the new computer for said tax program year.  From there you can do client file maintence, refresh homebase, or database maintenace to get them. to appear at the homebase.  

From there you should be able to open the next year (ie Proseries18) and simply transfer all the clients info to the homebase.  If done this several times.  It doesn't take long unless you have to use the database maintenance feature.  Good luck