Not bad, just a bit time consuming. No individual step is any harder than what is required to build up a crack + speedball (whcih is to say, basic ability to solder, through-hole solder and to carefully follow step by step directions), there are just a lot more components and connections to make.
I wouldn't recommend it as a first diy project just because it would likely feel overwhelming, but it probably would still be doable. Watching a youtube video on through-hole, and building a cheapie O2 board as a warm up (a $40 exercise), would give you all the skills you need though. Necessary tools for the mainline, IMO, are a decent temperature controlled soldering station, rosin core eutectic solder, auto wire strippers (Ideal 16-26awg are good), and a multimeter.