Rule for changing voice in simple future tense: 

Active VoicePassive Voice
Subject + shall/will + verb + object Object + shall/will + be + verb[past participle] + by/to/with + object 

Examples

Active VoicePassive Voice
I shall sell my house.My house will be sold by me.
She will help you to solve the problem.You will be helped to solve the problem by him.
She will submit her thesis tomorrow.Her thesis will be submitted tomorrow by her.
The law will punish her for her wrongdoings.She will be punished for her wrongdoings by the law.
Ram and Sam will clean the car.The car will be cleaned by Ram and Sam.
We shall overcome the bad times.Bad times will be overcome by us.
I shall surely invite you on my birthday.You will surely be invited on my birthday by me.
Nandita will give lecture on the impact of climate change.Lecture on the impact of climate change will be given by Nandita.
Santa Claus will give you presents on Christmas.Presents will be given to you on Christmas by Santa Claus.
The bodyguards will defend you from dangerous situation.You will be defended from dangerous situation by the bodyguards.