Well, 5 days will be enough for you to visit Hong Kong. You could spend one day in traveling Macau and then back to Hong Kong at night. Then, one day to the Ocean Park, the Victoria Peak and Central area. Another day, please go the big Buddha and Disneyland. Still two days left for your other interesting! Hong Kong's metro and buses could take you to these places quickly. So, please use them as many as possinle. As for the detail on how to arrange the trip, please refer to this website's suggestion: https://www.travelchinaguide.com/package/hongkong/