How do I download Topo U.S. 24K Southwest maps from a DVD into Basecamp on a MacBook without an optical drive?

In 2012 I bought Garmin's Topo U.S. 24K Southwest maps on a DVD. Now I want to use Basecamp on my MacBook, which doesn't have an optical drive. How do I load the maps from the DVD into Basecamp? I have a 2009 Mac Pro with an optical drive.

Looking at my Garmin account, I don't see a record showing that I bought the DVD. The price tag on the DVD package looks like I bought it at REI. REI shows my purchase history to 2016. Can I download the maps from Garmin?

I tried copying the DVD onto a USB thumb drive but all that copied was a small "Install Topo U.S. 24K Southwest v2" file, without copying the maps. I tried Command-Shift-period to show hidden files on the DVD but no files showed.

Then I cabled my MacBook to my Mac Pro with a USB cable. On the Mac Pro I opened "Sharing" in System Preferences and checked the box for "DVD or CD Sharing." I looked for "Remote Devices" in a Finder window under Locations on my MacBook but I couldn't find this.