Right then. I've now - finally - got my towbar, and the time has come (when it's not dark or raining) to fit it.

And with that I need some help.
First of all, please see:
Andrew Richardson's Photos - Towbar pics | Facebook for some photos of the towbar in question.
I've had a look under the back of the bus (sensible, no?), and I think I've sorted the position of the inner set of brackets - there are some plates just in from the towing eye on either side where the bolts line up nicely with the holes on the brackets. I'll have to measure to confirm, but that looks fine. My questions are:
1) Am I right with the positioning of the inner brackets?
2) Where do the outer brackets go, and will I have to remove the bumper to get decent access? I can't see, at the moment, where the outer brackets fit.
3) Do I need to drill any holes?
4) Where's the best place to hook up the electrics?
5) Where's the nut (other than driving) for winding down the spare wheel holder?
6) Why is it getting dark, why does it rain so much, etc etc
Thanks all.