How to proper remove Hyper-v snapshots

Hi,

This is a Windows Server 2008. One of its virtual machines has 8 snapshots in the Hyper-V Manager. Where do I start to delete the snapshots? From the bottom up or from top down within the the Hyper-V Manager. I need to free up diskspace on the Hyper-V Server. This is an important server and I don't want to loose any files.

Thank you very much.