Taking the ASRock NUC BOX-1260P apart is a relatively painless process, like its siblings. First, you will need to remove the four screws on the bottom, which will allow you to lift the bottom plate off and thus install your system memory, M.2 SSD, SATA HDD/SSD, and so on.
While further disassembly for system setup is not required, continuing further to do a deep clean remains a quick and easy process. To get the motherboard out, you will need to remove the rear I/O shield, which simply has two clips on the sides. With that out of the way, you must remove the two screws near the rear I/O, which secure the motherboard to the chassis. Once done, the motherboard can be lifted free of the chassis, but be careful as the Wi-Fi antennas are still connected. For this particular model, I was able to simply spin the black M.2 SSD bracket until the White antenna wire was free, at which point the board could be fully removed without needing to disconnect the tiny wires.
With the motherboard now free of the chassis, it's possible to flip it over to gain access to the heatsink and fan. The Delta fan used here is a BSC0805HA-00 and can be easily found on Amazon or elsewhere if it needs to be replaced, which is always nice. As for the CMOS battery, it is located under the fan.
As for other important parts or features, it should be noted the Wi-Fi module is an Intel AX211NGW. It sits directly below the M.2 SSD when the latter has been installed. Also, if you look closely, there is a pinout for clearing the CMOS that is easier to access than having to remove the entire mainboard and fan to force a CMOS reset via battery removal.
Finally, before I put everything back together, I installed the memory and SSD, a quick and painless process. For M.2 2280 SSDs, you simply use the provided screw to secure the SSD to the plastic bracket once firmly inserted into the M.2 slot. The memory is much the same, slot it in fully and then push down. Now, all that remains is to install windows via USB key, which is incredibly simple thanks to the Windows Media Creation Tool, as you can download the tool, set up a USB drive, and have Windows installed in less than an hour if your internet speeds are decent. I will say that due to Alder Lake being newer, the Windows 11 install did not detect the majority of drivers, including the Wi-Fi adapter. So make sure when you create your USB thumb drive for the install, you also drop the Wi-Fi networking drivers at the very least onto the drive, so you can have a fully operational system with fewer headaches than I did.