The frosted glass cover over the lamps in your video is held in place by the knob / nut at the very bottom. Support the glass with one hand, and loosen the knob / nut with the other by tunrning in a CCW direction. There will likely be a flat washer or decorative trim between the glass and the knob (be sure not to lose these parts). The knob / nut should only be hand tight, but that doesn't stop some people from using tools to tighten them.
Once the nut has been spun off, the weight of the glass will be in your hand. Gently lower the glass. Inside, you may find a washer and felt. Depending on yur particular glass, it may have neither - but if it does, you should reassemble the washer & felt in the same order as it is designed to help prevent cracking the glass if the knob / nut is overtightened.
Relamp, repair & clean as needed and reassemble in reverse order of disassembly.
I hope this was helpful!