To unlock the 7z file with the help of eSoftTools 7z password recovery software is the easiest way. it responds with three recovery techniques- mask attack, brute force attack and dictionary attack without any problem. It can break all password combination without any trouble. you can also add your personal dictionary as a clue. A preview option is also offered by this tool to get back first three letters of the password.

More info:- recover lost 7z password