VMware Tools for Mac OS X Server are not as robust as for other Guest OSes and does not have a GUI however there is a CLI named "vmware-tools-cli". It is located in the typical place, "/Library/Application Support/VMware Tools/", and you can execute it with the help argument to see what functions are available.
Personally what I do to shrink the virtual hard disk of my OS X Server Virtual Machine is to use Terminal and dd in the Guest to prep it for shrinking and then use vmware-vdiskmanager on the Host to finish the shrink.
In a Terminal in the Guest I use the following command to create a temporary file full of zeros.
dd if=/dev/zero of=shrink_prep.tmp bs=1048576
When the disk is full I delete the shrink_prep.tmp file and empty the Trash and then shutdown, not suspend, and close VMware Fusion.
In a Terminal on the Host using vmware-vdiskmanager with the -k argument and the target .vmdk file I finfish the shrink process. For proper syntax you can execute it without any argument and it will display the internal help information. vmware-vdiskmanager is located in the typical place, "/Library/Application Support/VMware Fusion/".
FWIW When I first installed OS X Snow Leopard Server the .vmdk files took up 10.69 GB on the Host's Hard Drive and after a shrink as described here the size was 6.02 GB and well worth taking the time to shrink it. It didn't take too long but it was nice to have the 4.67 GB of disk space back on the Host.
vmware-tools-cli doesn't currently support shrinking HFS partitions, so zeroing out the space manually is the only way to go for now.
In addition to the dd command, there is another way to zero out free space on Mac OS:
1. Run Disk Utility (in /Applications/Utilities)
2. Select the partition you want to shrink
3. Go to the "Erase" tab
4. Click "Erase Free Space..."
5. Make sure "Zero Out Deleted Files" is selected
6. Click "Erase Free Space"
Then shut down the VM and proceed with using vmware-vdiskmanager to shrink the disk. Of course make sure you don't have any snapshots before doing this, or the zeroed out space will be written out to the snapshot files, using up even more disk space.