At the Hong Kong Airport, there are frequent buses departing to Guangzhou everyday.
From Guangzhou to Macau, all of the buses will have a stop at Zhuhai. So, it is suggested that you take a bus to Zhuhai Gongbei Bus Station firstly and then walk through the Gongbei Port to enter into Macau. The bus could be catched at the Provincial Bus Station of Guangzhou (just to the west of Guangzhou East Railway Station). Many buses for your use everyday.