Assembly of the PCB is straight forward. To program the mcu I used a modified AVR-ISP-adapter: I had butt-coupled and soldered pogo-pins to a 6pin pin header together with some additional pin-headers for meachnical stability. The mcu can the programmed e.g. from the Arduino software using an external programmer (don't forget to first burn a bootloader to set the fuses of the mcu - the bootloader will be deleted again when the program itself is flashed).