A: Depends on the password.
If you found the password and just need to know how to use it in ZArchiver: and locate your file. Tap the file and select "Extract here" "Extract to..." A prompt will appear asking for the password. Type it exactly (it is case-sensitive) and tap 5. How to Create Your Own Password To protect your own files using ZArchiver: Long-press the folder or file you want to hide. In the configuration window, look for the Enter your desired password and choose Data encryption for maximum security. Summary Tip:
Brute-forcing is trying every possible combination of characters until one works. This is the only true "unlocker" method. You will need a PC (not a phone) and specialized software.