keychaindump OS X 10.8.5 how to run it?

I am using OS X 10.8.5 and fairly new on Apple systems and especially running scripts.

Can anyone describe how to start Keychaindump, does it need to run thru Terminal, or i need a additional program for it? I admin the machine, but need a lost password on a other users account, is Admin enough to run the program or do i have to be Root? I have access to the other user account.

Some passwords on this account i can find as wifi's etc, but i try to access the master keychain pwd, because the login id been changed, and so far there was not yet a reset on the keychain pwd.

The program i downloaded as .zip but i just needs more information how to run the script, sorry this maybe a inconvenient newbie question for most users here, but anyway thx in advance for any information provided to get me running it.

Here the link to the developer http://ift.tt/1t1ahZ0