I have a bathroom fan vent that doesn't completely come off, it stays attached but pops down (see attached images).
Should I clean these things using a ladder, or should I remove them and wash them somewhere else?
It does come off. You squeeze those wire clips together and the ends pop out of the slots they are in. Then you can take the entire cover off. After that there is usually just one screw holding the fan motor in place, take that out and unplug the fan so that you can remove it and clean it thoroughly with a vacuum cleaner.