How to open front for cleaning and if I would have to re light pilot?

From the part you are referencing with your question, it could be one of these Kingsman models: HBZDV3624, HBZDV3628, HBZDV3632 - however, we cannot be sure of this. We would recommend seeing if you can contact the previous owner or a fireplace specialist to find the model of your fireplace. In the meantime, please check this Installation Manual for the above mentioned fireplaces. If you have any further questions, please call us and we will be happy to assist you.