You have but a couple options if your LED's are too bright.
As mentioned, if the bulbs are replaceable style, lower lumen bulbs could help.
Many of the LED light fixtures in newer units are coming with non-replaceable wafer style LED bulb/modules. You simply can't replace the bulb/wafer. In this case, (as was also mentioned) you can replace the entire light fixture with ones with a built in dimmer.
An alternative to replacing the entire unit, (if you are handy/and able to do a little wiring modifications) is to install miniature DC to DC voltage step-down controllers to the voltage supply wires. They can be easily concealed in the existing housing.
are several examples.