No simple way of doing a mass restore of Files in EV 6 and before.
Registry Edits:
HKLM\Software\KVS\Enterprise Vault\FSA\PlaceholderService
BypassRecallLimitsforAdmins = 1
RevertItemsToPlaceholders = 0
Restart the Placeholder Service
Log on to the File Server as an Administrator.
Do a Search on the folder for *
Select Advanced Options, and select the option for a "Tape Search", this option will do a File open request on each file, and hence force a recall.