To delete the particular snapshot(s) from your existing backup store, Please use the “Redemption Backup Store Groom Tool” which can be downloaded from the following URL:
http://www.techsupportlive.com/index.php?_m=downloads&_a=viewdownload&downloaditemid=57
To know more about Redemption Backup store groom tool please refer to the document with the following URL:
http://www.techsupportlive.com/index.php?_m=downloads&_a=viewdownload&downloaditemid=59