Restoring a wallet from private keys (via the command line) is pretty simple. If you have the necessary information, with this guide you can completely restore your wallet. Note: you do NOT have to have your password to restore from keys.
You need to have 3 pieces of data from your wallet, or your .keys file which holds this info and the password to decrypt it. The 3 wallet components that you need are:
Then run the wallet command:
./monero-wallet-cli --generate-from-keys New_Wallet_Name.abc
Next, you'll be asked for the Address, the spendkey, the viewkey, and finally the new password for the re-generated wallet.
Running this with the correct parameters will re-generate your wallet files for you and allow you to set a new password.
If you run into any trouble, running
./monero-wallet-cli --help will show you the options available to you at wallet startup. Once you're inside your wallet, running the
help command will list the help for the commands available to you within the wallet.