How to block someone on Facebook without he seeing my name or picture in the Messages?

[Wuilly]

I want to delete messages I sent to someone, but I know, I can't delete it just from my inbox. So at least I want to block him so he won't be able to see my name and my profile picture when he reads the messages on the inbox. How should I do it? Please someone help me

[Nischhal Kumar]

You can block him and then in the future neither you will be able to see his name or pic nor he will be able to see yours
but when you will open your message box in his name will be replaced by the FACEBOOK USER
and same will be the case with him, when he will see his msg box in place of your name it will be written FACEBOOK USER
but on reading the messages you can guess the names even afters years and years

[Daniel]

Go To His Profile than Click on the Circle Than Click on The Block Button