Rule for changing voice in present perfect tense from active to passive – 

Active VoicePassive Voice
Subject + have/has + Verb[past participle] + object Object + Have/Has + been + verb[past participle]+ By/to/with + Subject 

Examples

Active VoicePassive Voice
I have made a clay doll.A clay doll has been made by me.
The man has helped me a lot.I have been helped a lot by the man.
She has saved the boy from drowning.The boy has been saved from drowning by her.
My friends have informed me about the incident.I was informed about the incident by my friends.
The lion has hunted a deer.A deer has been hunted by the lion.
Mother has ordered us to clean our room.We have been ordered to clean our room by mother.
He has bought a motorbike.A motorbike has been bought by him.
He has solved all the problems.All the problems have been solved by him.
The cow has eaten tender grass.Tender grass has been eaten by the cow.
The batman has defeated the joker.The joker has been defeated by the batman.