4
Create a file in your root and paste this:
include_once (mainfile.php);
$member_handler =& xoops_gethandler('member');
$from_group_id = 2; //set this
$to_group_id = 4; //set this
$usersid = $member_handler->getUsersByGroup($from_group_id, false, 0, 0);
foreach ($usersid as $uid){
$member_handler->addUserToGroup($to_group_id, $uid);
}
?>
Don´t forget to set the groups id.
Atention, I did not tested this.