First you have to locate the Virtual Machine in Finder. With Fusion 2.0, you can do this using the Virtual Machine Library. With Fusion as the active application on your mac but the virtual machine not running (either suspended or shut down), in the Window menu select the Virtual Machine Library item. It may take some time for this window to refresh when it opens (can't do anything while the ball is spinning). Next Right click, if you have a multi-button mouse attached, or ctrl+click if you are using the trackpad or an Apple mouse then select the Show in Finder command. The icon that is highlighted in the newly opened finder window will be a vmware virtual machine package if you created the virtual machine with fusion, or it may be a file within a folder if you created it with a vmware converter. NOTE: From your posts so far I am assuming you have not used Apple's bootcamp to create your windows machine on your mac, that is a totally different discussion than this and don't try this on a bootcamp partition.
Assuming you have created this virtual machine with fusion, you simply drag the .vmwarevm package to a suitable location on your external drive (I would create a folder called VMs, or Virtual-Machines or something so you can exclude it from TM backups easily). Depending on the size of your VM this copy could take some time (I see about 1 Gig per minute copying disk to disk so set expectations accordingly). Once the copy is complete, double click on the icon that is now on the external drive. You will be prompted as to whether you copied the VM, or moved it. In your case you want to indicate that you have moved it. Once the VM is up and running, and you are satisfied that everything is OK with it then it is OK to delete the original VM from its' original location. In general I would come up with some backup plan for your VM. I shut mine down at least once a week and copy them to another drive for backup.
If you created your vm with a converter and when you did Show in finder it was highlighting a .vmx file with the same name as your VM, inside a folder with a similar name then you just want to copy that whole folder, and when testing the new copy you double click on the .vmx file. (This is probably not your situation, but trying to cover all bases).
In either case, once you have launched the newly copied VM the first time it will show up in the Virtual Machine Library, or in the Open Recent list of Fusion's File menu. Once you have deleted the old copy from your external drive that entry should become unavailable or go away.
This movement of the VM should not affect your licensing at all, but it is key that you respond that you have moved the VM when prompted by Fusion when first opening the copied VM. I have 2 VMs that I sometimes move between external drives and run them on a Windows host, and as long as I indicate that I have moved them (which is what I have done) Microsoft licensing does not come into the picture.
Message was edited by: gbullman
You probably also want to take a look at this document, it gives you a lot of good information about Virtual machines http://communities.vmware.com/docs/DOC-1110
