I those two links are transfer thiggys and not alot of people put mods on their fileshare so thay are hard to find on b.net, and they get deleted Look here, some of the links still work http://www.ibotmodz.net/forum/index.php?/topic/4653-all-halo-3-mods-450-mods/
You need a transfer device, you can get one from microsoft by calling them but i think you have to pay now. Or you can get one of these http://us.codejunkies.com/Products/XB360-Xport__EF000191.aspx or http://us.codejunkies.com/Products/XB360-XSATA__EF000192.aspx Then you need a resigner, which you can find here http://www.ibotmodz.net/forum/index.php?/forum/120-programs/