lowering current of a constant current driver
Since the OP has provided some information on the chip I will extend the below  comment to include the specific case, but it should apply to most modules of this type: 


  There is probably a sense resistor in the module, so if you increase
  the value of that resistor in the ratio 1.5:1 it should regulate at
  the lower current.
  
  Look for a low value resistor, possibly of a larger size, maybe in the
  low ohm or sub ohm range, it may be connected directly to one side of
  the load.




In this particular case the sense resistor is 2.7 ohms, so the current can be reduced by increasing the resistor to something like 4.7 ohms. In this case, it is not connected in series with the load, but on the low side of the switch (connected between the source of the N-channel MOSFET switch and the supply negative rail). The chip is an FT886A-RT from Fremont, and the datasheet is rather sketchy, however here is a typical application circuit showing the sense resistor: 



The comparison voltage is 500mV and they appear to assume ripple in the input so a lower average current than you are observing with a DC input to the chip. If you greatly decreased the current it might be necessary to increase the inductor value, especially if the input voltage was expected to be relatively high compared to the module design maximum. The chip is advertised as having protection against inductor saturation so even that would not be expected to kill the chip, just affect the operation.  



If there is a lot of ripple, due to poor input or output filtering, remember that the perceived visible light output (in the normal working range) is roughly proportional to the average LED current, but the maximum LED current is proportional to the RMS LED current, so the further you stray from smooth DC the less light output you can safely expect.