You've already done the smartest thing you can... bought the manual.
Just recently installed 10" Monkey bars on my StreetGlide as well. I also installed a new ss/chrome cable. It's the same length as the stock cable, but I just wanted to add a better looking cable to the whole handlebar mod. If you have any questions at all, feel free to PM, and I'll be glad to help you through it. Not very difficult at all, just remember the fundamentals of tearing it down and swapping out parts; don't over-tighten fasteners, make sure mating surfaces are clean, and pay close attention to how everything goes together before you tear it down. Take pics with your phone as you go (from several different views), so you can refer to them as you put it all back together.
I watched that vid last night. What I didn't understand was what was he doing under the derby cover on the left side?
Clutch adjustment. Just watching that segment alone doesn't really offer much info. The HD manual does a pretty good job of explaining this segment. It's been a while since I watched that entire video, but as good as it is, it's not the end-all/be-all. I can't remember if it details the segment of installing a NEW cable into the trans case.
Gunny mentioned the *****, that's a good note. also be sure to orientate the internal snap-ring properly when you put it back together. Thoroughly read/comprehend the clutch adjustment segment, and you'll be fine. Just a bunch of little details that will insure success. Again, don't hesitate to pm me any specific questions. Good luck!