Time Machine Disk Permissions Issue

I've got an external hard drive that was being used as a Time Machine backup for several years. I've moved this over to another computer and I want to access specific pieces of the backup, but they are locked.

Specifically, a large Lightroom library connected to many photos on the drive.

How can I unlock the entire disk so I can access and use the files however I'd like? Its really a complete nightmare and I just can't get it to work.

Even when I try to open a lightroom catalog file from a backup on the drive it says specifically:



Moreover, when I added disk permissions from the top down, it still shows up as locked...

 

Did everything on that list, identical problem persists D: