To update the code using the copy and paste method you need to:
Click the RAW button from the code page
Copy everything shown on that page
Paste it over the previous version of the code in the IDE
Click Save
Click Publish
The best way to use community submitted SmartApps is to set them up with GitHub integration because they’ll turn purple when there’s a new version and you can update them by clicking the “Update from Repo” button in the IDE.
These are the settings you’ll need to use to integrate my SmartApps and/or device handlers.