The light is unlikely to be 1600 lumen, it's probably more like 300-500 lumen depending on the focus, but still a decent light.
As for the conversion to infrared, it'll depend on the driver of the light. The simplest might be a driver swap to a lower power buck driver and switching the LED to a infrared LED. The current driver might work, but the current (amp) output of the driver needs to be lowered unless you can find a IR LED that can take 3 A continuous.