Do you have any idea of the password may have been? If you have some idea or a list of password to try, you can generate a list of passwords and use a script to test them all out. Without at least some idea of the length or letters the password may consist would take the program years to crack a relatively simple password.
Multibit themselves provided a script:
https://multibit.org/help/v0.5/help_lostOrForgottenPassword.html.