Now it's time to program the microcontroller. Due to the tight space, the 5 pin ICSP programing connector is located on the backside of the PCB. Insert a 5 pin header's longer side into a PICKit 2 or 3, or connect it to another programmer. Then insert the short end of the 5 pins into the holes on the back of the PCB - marked ICSP. Make sure that the MCLR pin goes into the hole with a triangle mark. PICKit has a same marking to indicate the MCLR pin.
Download the HEX file provided, fire up Microchip IDE or PICKit software, and program the PIC.
*Since the battery is not connected, you need to supply the power from the programmer. You can find this in the "Options" menu.
Refer to the screen shots - I recommend setting the Vdd to 4.9V, just to be sure not to let the zener diode shunt too much current. (I never had any problems using 5V so for, but better safe than sorry.)
*** UPDATE ***
The assembler source file (wave_jt-1.1.asm.zip) is uploaded. Now you can modify the firmware to modify and/or add new functions!