The LED is mounted onto an aluminum PCB for heatsinking, and it also makes it easy to solder in. Simply connect to the big + and — pads on the PCB (there are two of each).
The best way to drive these LEDs is constant current, @ 350 mA, but you can get away with under-driving for compactness. At about 3V, the LED draws ~200 mA, so connect two Alkaline batteries up directly with no resistor for a basic bright lamp. You can also try driving it directly with a 3.3V power supply, that will probably work OK as well (although its not ideal) — that’s what we did when we made a vintage LED bike light using a 1W white LED.
Datasheet for the BL-HP20AWCL 1W LED