Please check the below.
●Hand screw type
There are two screws on upper part of the cover.
Turn the screws counterclockwise to take it off, and you can remove the cover
If you want to change the light bulb, please bring the old one to home center to get the same type of it.
Remove the end caps from the both sides. Then, pull out the cover.
●Top opening type
The light bulb can be removed from the top without removing the cover.