Inside your boot if you remove the trim that covers the back (where your ligh etc are) you will find quite a few nuts that need to be removed.
As you can see on the pic i attached there are 4 in the centre behind where it says skyline on your rear bar (circled in red and numbered 1).
There are two on either end of the rear bar down in the side wells (numbered 2).
There should also be one bolt on either side that will be accessable from under the car (numbered 3)
You will also need to remove your reversing lights which a located beside the number plate and the number plate lights above the number plate as well as removing your numbr plate holder from the rear bar (you will see a bolt behind the number plate that attaches it to the bar).
Easy as