To help us to feel more comfortable on the roof, Grandpa and I installed a rope that we could swing from for extra leverage.
Installing the hip flashing over the corners of the porch roof proved to be a 90% single man job, with a second person required just to help align the corner for the first few screws. Once again Grandpa went to work landscaping out the areas where puddles from the previous rain were visible. He was gracious enough to interrupt his work for a few minutes each time I tried to align the hips.
The hip flashing was rather straightforward to install. I cut a V in one end of the flashing, headed up on the roof and pressed it in as tight as possible at the top of the hip - taking care to ensure that it covered from one side of the corner gap to the other. Then Grandpa marked under the bottom corner for the cut there.
I climbed back down off the roof, cut a point at the bottom, and then used some self-adhesive "universal foam" under the hip flashing to ensure that pests wouldn't have a gap to get from above the roof to below. The hip would naturally shed water and snow, but there would still have been a space between the flashing and the bottom of the steel otherwise.
Once again Grandpa ensured that the bottom of the hip flashing was over the corner of the roof, and I drove screws down through the hip and into each rib of the steel roofing. Driving the screws through two layers of steel was slightly different than on the main part of the roof where it was a single layer of steel over wood. I found it was fairly beneficial to put my full weight behind the screw as I was drilling, to help prevent the screw from "lifting" the hip flashing off the roof until the screw bit into the rib of the lower steel.
The hips certainly accentuated any imperfections in the junction between the two roofs, but it wasn't as noticeable from down below, especially if you weren't specifically looking for flaws, so I'm not getting myself worked up about it.
With the hips complete, now I just need to find a day that's clear enough, and with me in physical shape enough, to get up on the roof and install the endwall and transition flashings. I don't want to begin to insulate the inside of the sauna until I am certain that it will shed water everywhere.