The Google Slideset Files are all deliberately view only. This means you can look at the slides, but you can't click or make any edits. This is because they are the master files. You can make a copy of the file and then use/edit the slides any way you choose!
Choose your case.
Click on the link for the "Google Slide Room".
This will open in a new tab as "View Only" Google Slide.
Click Google Slide File → Make a Copy → Entire Presentation.
Copy docuemnt box pops up. Name case. Press ok.
Tip: Name slide set something generic like "Room A" so the title doesn't contain spoilers when you share it with your learners!
New tab will open. This is your editable Google Slide document.
VERSION HISTORY: Save Unused Version before you make edits. This will allow you to quickly restore the document to its "unused" state between uses. Click File → Version History → Name Current Version (ex: "Unused Case".
SHARING SETTINGS: Change Sharing Settings so your partipicants can edit the document (this is essential - this is how they will run the case!). Click Share (Top Right) → General Access → Anyone with the Link → Can Edit.