Rule for changing voice in future perfect tense: 

Active VoicePassive Voice
Subject + Shall have /will have + verb [past perfect] + Object Object + shall have / will have + been + verb [past participle] +  by/to/with +subject 

Examples

Active VoicePassive Voice
The director will have directed another movie.The director will have directed another movie.
The monkey will have eaten the banana.The banana will have been eaten by the monkey.
I shall have used the key to open the door.The key will have been used to open the door by me.
I shall have said the truth.The truth shall have been told by me.
The boys will have played hockey.Hockey will have been played by the boys.
The photographer will have captured beautiful pictures.Beautiful pictures will have been captured by the photographer.
I shall have cleaned the clothes.The clothes will have been cleaned by me.
He will have defeated you in the race.You will have been defeated in the race by him.
My friends will have supported me.I shall have been supported by my friends.
Trisha will have told you the truth.You will have been told the truth by Trisha. / The truth will have been told to you by Trisha.