How to restore Apple TV to factory setting

Hello,
When I try to restore Apple TV in iTunes, I ended up with an error message. I do not understand the root cause of this problem. I tried some steps repeatedly but nothing works. I am not technical strong so feeling tired of this. Someone could help me to solve this error. Thanks for your help.

iTunes
Your Apple TV has been restored to factory settings. Please disconnect your Apple TV from your computer and reconnect it to your TV.
