We received the ‘my cloud Personal Cloud Storage’ of my brother, who passed away.
We don’t know the credentials…
Can some one tell how we can access data on the hard disk…?

He had made a lot of foto’s…

Thanks !

Your post is in the My Passport Wireless section, but your question is about the My Cloud.
I’ll presume it’s the latter.

The manual can be found here:

but you’ll need to determine by looking at the label which version you have.

The procedure to reset the admin password is described in the manual.