Assuming you have copied the attachments to a directory on the new server, add this to config.php to enter into debug mode:
Under:
<?php
Add this line:
$config['Misc']['debug'] = 1;
Then to change the attachment directory:
Admin CP -> vBulletin Options -> Version Info and Other Untouchables -> File Attachment Path
Remove or comment out the debug line when you are done.
Under:
<?php
Add this line:
$config['Misc']['debug'] = 1;
Then to change the attachment directory:
Admin CP -> vBulletin Options -> Version Info and Other Untouchables -> File Attachment Path
Remove or comment out the debug line when you are done.