heres the pen i got... it has this rainbow lanyard on it, all the ones ive ever had, had it, so you might wanna look for that

heres the part that houses the chip

here, you can see that its protected.. its basically just a black blob

and heres the chip... just take off the leds, button and battery spring and solder wires in their place, you also need to solder a wire to the space that used to make contact with the housing

Heres all the solder points... the 5VDC + and Led common + are the same, but since theres already two different joints, i used it this way
