Can you dim already dimmed LED lights
What you want is not possible, these lights work from mains voltage (240 V AC) which the LEDs in the lamp cannot handle. So there's a power converter circuit present that transforms the 240 V AC into a (much lower) DC voltage (at a high current) that the LEDs can handle.
For dimming usually some form of PWM (switching on/off faster than human eyes can see) to reduce the power to the LEDs. Other dimming schemes are possible also.
You cannot control the dimming other than through the remote control because a smaller input voltage (for example 180 V AC) would be compensated for by the electronics. Or the circuit would just stop working properly.
The lowest setting at which the LEDs will work is determined by the design of the circuit that powers the LEDs. You can only influence the lowest setting by changing that circuit and that isn't something a beginner can do. It might not even be possible for an advanced engineer to do that as the components (chips) that are used might determine the lowest brightness setting.
So if you really need these lamps to output less light you will need to replace them with ones that have a lower light output (like 2 W instead of 5 W).