1. Open the Recovery Manager for Exchange Management Shell
2. Run the following cmdlets, replacing -ServerName with the name of the Archive Manager server.
$AMSourceStorage = Attach-RMEArchiveManager -ServerName ArchiveManager -Authentication Windows –LoadAllMailboxes
$AMSourceStorage | Get-RMEMailbox | % {
Restore-RMEMailbox $_ -TargetFolder (Attach-RMEExchangeMailbox -ConnectionMethod Auto -MailboxName $_.DisplayName)
}