I know that Facebook has no possibility to merge two accounts. Can you please suggest the way to do it? I?

Thats not Possible there are no Features or Tools that will help you do this Especially Because its against the TOS Terms of Service of Facebook to make more then 1 Account if Facebook Catch's you with another Account they will Delete your Accounts

They can tell when you make more then 1 Account

If you know that it is impossible then, and state that, why on earth do you think someone will know how to, if you already know it is impossible?

that's just not possible - in fact, it violates the terms to even create more than one account, which is why there is no option to do it - also, it seems odd to me that you would state that you know it's not possible, but then you ask how to do it anyway

I am not an advanced user, so I am unable to perform actions recommended by Facebook. I need more simple explanation.