Snapshot on Hyper-V (Windows 2008 R2 Server)

Hi.

We are running Windows Server 2008 R2 64 bit with 5 virtual servers.

Unfortnatrly we have started the prossess Snapshot and it taking up critical space on our main server.
How can I stop the prossess and regain space on the server.

Have search on the net, but not yet found a good discription how to do it.

Thank you in advance.

Dag N