I can't figure out how to disassemble the darn thing. It has this plastic retaining ring on top that I can't get out. Any ideas? Any pics of the disassembly?
Use a pair of needle nose pliers in the two slots in the plastic retainer. Perss down evenly on the metal inside the slots, and the LED module will drop out the battery tube. On the module you will see two angled black plastic tabs. Press those while pulling the metal cover off, and you are ready to mod. Watch out for the small metal disk that contacts the anode of the battery! It is easy to lose if you are not careful.
Note: before you remove the LED from the metal cover/heatsink, mark the positive lead on the LED.
Once you get the light apart, you will see that the contacts for the LED need to be fabricated. Use your imagination here. I used insulated wire.
The light is a lot brighter with the Seoul LED, but it is very difficult to get a perfect beam. I spent hours trying to get rid of a halo effect, with little success. I have done over 50 Seoul mods, and this was the most aggravating for me.
Good luck, and most of all, have fun!