The instructions for the hardware hack and the firmware can be found in my Github repository: https://github.com/tscha70/LEDCandle You can play around with the code available for the Arduino IDE. I have to admit that it's quite tricky to work with an ATTiny85, but it's also a lot of fun.
You will need some of these lights:
Lunartec set of 6 rechargeable LED tea lights with charging station, remote control