I may the last guy to the party, but I just found about a dozen videos on YouTube from QiDi. They cover basic maintenance activities for the Qidi printer, and include replacing: the extruder, half the extruder, the filament drive gear, the Zaxis motor and threaded rod, the thermocouple, and the extruder drive steppers. Also leveling the build platform, testing the X, Y and Z limit switches, tightening the screws on the X and Y drive stepper pulleys, building and installing the acrylic covers, and replacing the nozzle and PTFE tube (I always wondered what that big freakin bolt was for).

All of these turn up on You Tube in response to a search for "QIDI 3d printer", then apply a filter for this week (or today if you're snappy).

I expect that Qidi will eventually post these in their sticky thread.