You can survey using FMX with free WM Survey plugin, see Chapter 9 of the FMX User Guide. The survey will produce the multiplane.txt file that will be stored in the FMX in folder of the field that you surveyed. Insert a USB stick to the FMX to download and save the multiplane.txt file.
It can be directly imported to OptiSurface Designer. You can design the field using the software and the output will be a control file (.gps file) which you can then load back to FMX and perform the landforming operation with Field Level II plug in. You may have to buy the Field Level II plugin from your dealer.
Also, see this article in our knowledgebase to guide you in the survey operation:
How to Survey a Field for Landforming Design
Below show some clips from FmX User Guide v7.2a