Second Jawaid's thorough reply. The Quran doesn't once combine the word 'sunnah' and 'Rasool' into a phrase 'sunnah of the prophet'. It is only some time after his death that Muslims introduced this phrase and concept. As for following the Prophet, we need only check what the Quran has to say, and then follow that.
Several times the Quran records that the Rasool was told to declare: "I only follow what is revealed to me." (6:50, 7:203, 10:15)
Also at 10:109:
(O Messenger), Follow what is revealed to you and be steadfast in adversity until Allah issues His Judgment. And He is the Best of judges.
Logically then, the example of the Prophet means simply 'follow the Quran as he did'.