How do I edit the welcome tour?
The welcome tour is an extension, which means that you can edit it by going to Backend > Extend > Extensions then click the Tour extension title followed by the Slideshow tab.
Here you can define new slideshows for backend and/or customer area.
Each slideshow can have multiple slides where you can upload images, set the text, sort order and so on.
It is important to note that the app will use the latest slideshow for each app area, for example if you have 3 backend slideshows, it will only use the most recent one.