أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
from professional point of view, you should ask the person who protected the file.
If that person you. you can use some programs to break the password if it's for excel file. But if it's for sheet only it's easy to break using simple algorithm.
Hope that provide some help.
Regards
