How to Get Files from Mac Hard Drive to Windows 10 PC

Yes, you can transfer the files from the My Passport for Mac drive to your Windows PC across your home network.  How long it takes to transfer 400GB will depend entirely on your home network speed.

There is a chance that the drive was pre-formatted as ExFAT (even though labelled "for Mac") in which case it should mount under recent versions of both macOS and Windows.  If it is ExFAT, you should be able to connect it and get to work.

Of course, it may also have been pre-formatted as HFS+ (Mac format).  If that's the case, I highly recommend MacDrive (mentioned in a prior post).  You'll be able to connect the drive and just get to work.  You'll also be able to use the drive as a Scratch Disk and to export back to.  (Of course, I'm assuming that the drive is USB3 or faster and that the footage will play smoohtly at USB3 data transfer rates.)

You're running Premiere Pro CC2019, correct?  You may already know that you'll need that as well for the Apple ProRes422 support on the Windows side, but it's worth mentioning.

fat 16 and 32 have serious file size limitations.  On researching exfat I did hear about some compatibility problems.  Always a good idea to test before trying in a time critical situation (this is the voice of experience speaking)

I know it's a drive from your client, but just in case; If you format a drive as FAT or exFAT format you can read/write on both windows and mac.

I used to have a utility called macdrive that would allow you to read and write macformatted drives...

https://www.macdrive.com/

Worked great when I needed to do that...  Next time you can ask them to export to an exfat drive which may be readable on a windows machine...  I understand there can be compatibility issues with exfat drives on windows.

There are also utilities for the mac to write to a standard windows formatted drive

https://www.paragon-software.com/us/home/ntfs-mac/

And there may be some free options out there...