Only stand on those pitched roofs if you want to be seriously injured or dead.
For windows like that, try positioning your ladders above the window to get a better angle; or a double A Frame ladder into the top corners of the window opening. If your ladders aren't long enough to get above the window, then I'd put them up against the pitched roof and try to clean the windows with an extension pole; but even that would be slated (I bet) by guys who're 'elf 'n' safety aware.
But do not - repeat do not - stand on those pitched roofs; that is just asking for trouble.
A better, quicker, SAFER, and a cost effective approach (I think) would be get a backpack and do all of the first floor windows with it.