First, welcome to the forum. As far as the headlight, there is only one light bulb that you need to replace. The cyclops is by far the best on the market, outside of doing the full headlight swap to the expensive LED Revo or Hoglight one. The cyclops is a simple plug and play bulb. Make sure to get the upgrade "Ultra" as the high beam is a big improvement over the regular. My wife ran this in her bike for 3 years before I upgraded her, and she loved it. I have put in many of these in customer's bikes and all great feedback as well. There will be a rubber boot and you will want to drip the center of that to fit over the bulb. You will understand once you have the headlight apart.