David Aldridge wrote:
I need to change the aerial on my roof, and I was hoping for some
useful advice before I go up there. The problem is, that the roof is
a little unusual - rather than the normal inverted 'v' there are also
side angles too which are quite sheer. See picture
http://www.dmaz.demon.co.uk/house.jpg my house is also the middle of
a terrace, so there's no access from the sides.

So any kind soul feel like giving me some advice? - even if it's 'get
a professional'. (in which case how much do you think that might
cost?)
Get a professional in. Your life is not worth it. Cost £150.
Reminds me of the story of the guy who threw rope over roof to hold onto in
such a situation.
He tied it to towball of car. Wife did not know and drove car off pulling
guy over roof to his death.