I recorded myself adding a second brood box yesterday. I think it went okay besides being clumsy but I am sure I did something wrong or made poor assumptions.
Please watch and provide feedback - no matter how harsh.
Oh, I left a bit in when I got a serendipitous phone call.
Hi Bobby
Nice video! Thanks for shearing! I am getting my bees next week and i am really excited! 
Cheers
Flo
Bobby,
Thanks for posting I am enjoying watching your journey. I’m up north and I haven’t gotten my bees yet. I know your plan wasn’t to get honey this year but at this pace if the flow is good. I could see you needing to use the flow frames in 4-6 weeks.
Did you consider putting the new brood box underneath the old one?
@Rick_Gougis thank you. It’s a lot of fun. I’m quite clumsy at this point and I have no idea if I should have removed the drone comb or not but I left the one clump just in case.
I thought about putting the new brood box on the bottom after seeing a few people use that method but I figured that with the onset of warm weather (mid-seventies here for the foreseeable future) just moving a frame of brood up would be good.
Seems to be a 75/25 split on what method beeks use.
If they start neglecting the lower brood box, I may swap them then.
I am adding a second brood box to my other hive today. I could experiment…maybe.
Go for it! Then tell us all about it over time! 
I ended up not adding another brood chamber to the 10-frame hive. Those girls only have 6 frames drawn. It is going to take another week for them to get to 80%.
I DID see a small hive beetle though. Grrr.
I manipulated a couple of frames to encourage some drawing on the outer frames.
Nice brood pattern in that hive but I did not spot the queen. Saw eggs though!