First of all, one has to confirm from his heart that Allah is the only god, all power belongs to Him, and no being other than Him can possess any power to provide help or cause harm. A person who affirms these truths conclusively serves Allah alone and never ascribes partners to Him. Allah advised people that they must turn completely to Him to be saved from idolatry. 

It is Him alone you call on and, if He wills, He will relieve your affliction; then you will forget what you associated with Him (your idols). (Surat al-An’am: 41)

The radical change experienced by a person who is freed from ascribing partners to Allah and turns to Allah, first occurs in his heart. The person who is saved from ascribing a partner to Allah gains a totally different point of view and mindset. He now leads his life which, until then, he had pursued under the sway of certain rules of ignorance, as well as his own wishes and obsessions, for Allah’s approval and pleasure alone.