If the RRT-2 is anything like my old style (XRE) RRT-0, after de-soldering the leads from the LED and removing the PCB there will be two screws underneath that need to be removed. The head can then be disassembled. Be careful not to lose the spring and ball bearing that reside in the adjustment ring upon disassembly. Also take note on how the driver is clocked inside the head for proper re-assembly. Hope this helps.