If you don't want to change the original lxlock script, you can copy the script to /usr/local/bin/ and change it there. The modified script will be used, since the "local" directory is mentioned earlier in the environment variable called PATH. Upgrading the operating system will not change the script in the "local" directory, as far as I know.
If you don't want to change the original lxlock script, you can copy the script to /usr/local/bin/ and change it there. The modified script will be used, since the "local" directory is mentioned earlier in the environment variable called PATH. Upgrading the operating system will not change the script in the "local" directory, as far as I know.