How can I see a PDF if I don't know the password?

Hi there,

My father recently passed away, and unfortunately left no will, or instructions upon his death.

My mother and father were always kind of secretive with each other, and never told each other things, as they never thought it would affect them.

Since my father passing, I've been going through his PC, and whatever records I could find.

I since stumbled on a password protected PDF named "Finances and Money", understandbly why it was password protected. 
Problem is, now that he is gone, no one knows the password, and I am attempting to help my mother find whatever assets, and properties he might've owned.

Is there anyway of me removing a password from a PDF without knowing the password?
I'm sure somehow this is gonna be a controversial topic.

Thanks in advance.