DON'T DO THIS! Snapshots are used in chains. This means that all of the .vmdk files are in use and removingg one of them woud break the snapshot chain.
I assume you tried to create the snapshot with the VM powered on? Anyway, please attach one of the latest vmware*.log files as well as the .vmsd file to which can be downloaded from the VM's folder to a reply post and let me know which .vmdk filenames show up for the virtual disks in the VM's settings (to ensure we don't make a mistake). With this information it should be possible to recreate the .vmsd file (this file contains the information for the Snapshot Manager) to allow you to delete the snapshots one-by-one.
André