|Is this a shared file or are there 40 individual copies?|
If there are 40 copies, delete yours and have any one of the other 40 send you a new copy.
If it's a shared file, are you sure the password is being requested by the file and not by the network drive it is stored on? Perhaps you don't have the correct permissions to access that drive.
BTW...we do not offer password crack/removal advice in this forum. Requests are typically deleted by the admin.
I believe I've offered a workaround without violating that rule.