Hiya, some go inside the chasis some go outside the chassis. you will need an extra bolt (or studding) for one of the rear mounts (some companys send you one with there guard, mine didnt)
If it goes outside of the chasis, the bolt that goes through the steering drop arm can be a real bitch, In my case I had to replace it by the time I had belted it out!
I replaced it with a length of studding.
but all in all not a difficult job.
Andy