Decoding Morse code is not difficult, but it can be tedious if you have to do it manually. One way is to open the MP3 file in Audacity:
Now you can easily see the dots (short tones) and dashes (longer tones) and decode the message.
The Morse code of this challenge decodes as
"The password is 71401"
Or you can try to decode it with a program, like this one.