You can edit the .vmx configuration file directly from Finder when the Virtual Machine is shutdown, not suspended, and VMware Fusion closed! Have a look at: 
Work with Virtual Machine Packages
Or you can explicitly follow the directions in the previously posted VMware KB Article: Editing the .vmx file for your Fusion virtual machine (1014782) (Which contains a variant of what I originally said, although just use some common sense! 
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