The easiest way to recover lost or forgotten 7z file password is by applying eSoftTools 7z password recovery software.it has simple GUI which makes easy to use for every user even he is a technical or non-technical person by applying these steps:-
• Download and install 7zpassword recovery software.
• Select the file which has to be open.
• Choose one recovery attack from given three – Mask attack, a
Brute force attack, and a Dictionary attack.
• Click to proceed button to run.

More info:- https://www.7zpasswordrecovery.com/