You could take off the resistorpack, solder some wires to the pads going to the leds (or directly to the pads going to the resistorpack), solder a resistor to each wire (same value as the resistorpack), tie the other end of the resistors together and solder on another wire and connect this wire to either 5V or GND depending of which side of the leds this whole thing is connected to.

Stig