I'm happy that you asked!
How to install scenarios with Copy/Paste:
1) Create a new text file in your Dangerous Waters\Scenario folder. Rename the file to change its extension (file type) from ".txt" to ".mu"
2) Copy the data for a scenario you want.

(Image: Step 2)
3) Paste the data into the .mu file created in step one and save it.
All Done!