I just did an upgrade like this with an 8600k and an Asrock Z390 that is going pretty well so far. Upgraded the ram to Corsair LPX 3000, removed the 2.5" drive, and added a 1 TB Samsung 970 Evo to go along with the Samsung OEM drive Corsair had in the One originally for 1.5 TB of NVME storage.
My only issues are figuring out where the top fan connects to so I can reconnect it to a header on the motherboard to better control it's speed and figuring out the pin out of the RGB header as I forgot to look at it when I took it off the MSI board and I don't want to blow out the header on the AsRock board.
Does anyone know the pin out of that cable? It has two white wires, two black, and one has a gray dot on the heatshrink? That or does anyone have a picture of it connected to their board where I can see the silkscreen on the pinout?