all the advice seems to be its difficult to do!!!
But I'm fairly confident to have a go now!
Welcome to the forum.
They are certainly not 'difficult'. Just very simple woodworking. Some machines certainly make the job even more simple, but they could be made using entirely manual tools as long as the drawings are adhered to and the worker has the skill to do it sensibly (must finish with boxes to the dimensions stated and they must be square and 'stackable' without gaps between the boxes).
Personally, I've never found it worthwhile to make a brood box. Cedar cut to size ready to assemble with no problems of checking dimensions is so easy and not time consuming. All of mine (I think) were bought in as seconds, and most were deeps to which I have added an eke. I do have about ten supers 'in the pipeline'. Making in multiples of, say, ten is a far better idea.
If I were to have one power tool, the obvious choice would be a table saw. Thinking about the job a little more closely, I would change that to a router - but only because one can do so many more operations with a router, so it could be used for a multitude of other jobs - even though it may not be the most efficient tool for this particular purpose (and I would not be making the frames that way!).
But, I am like some others on here - power tools include various saws, planer/thicknessers, routers, screwdriver/drills and even nail guns. Choice of hive type can make a big difference to the amount of efffort required.
Like others on here, I am now buying/trying plastic hives, as an alternative material. I say 'plastic' because someone will remind me I have a beehaus as well as expanded polystyrene (EPS) units around the place. I still think I may make floors and roofs for the EPS ones, all the same.
Remember the dimensions are all important, to avoid bee related problems when in use! Oh, and make a 'deep' roof while you are at it. You will not regret it, if you do.
Regards, RAB