yeah that 2nd mount is from a cusom exhaust of some sort.
what you need to do is loosen the clamp between the centre section and backbox, its 2 13mm's you dont even need to jack it up if your thin like me, then loosen the 13mm on clamp that goes round the backbox (need to use 2 13mm's one to hold the bolt one to loosen the nut) now you can twist the backbox to straighten it up and re do the 2 13mm's on the clamp, then lift the box up to the height you want it to sit (use a jack to hold it if your just doing it on your own) and tighten the rear hanger bolt.
done