1)It would be awesome to start with a screen-recording of you doing it yourself: The screen recording could be easily done in android devices, while in IOS devices it would be a little complicating for screen-recording to work. For iMacs, by opening QuickTime, you can start screen recoding easily.
2)Then summarize the important bits and list them into bullet points: Know what you are planning to teach, know your audience, what would they want to know. Find a easy and simple way (Bullet points in the video) to deliver the message clearly without making them bored reading texts.
3)Then edit the video of the screen-recording: Cut the unnecessary bits of the video which is time consuming (Loading parts)
4)Then put the summarized important bits into the video matching it: Include the bullet points mentioned above, match them to the video, by listing the bullet point when a part needs to be explained, allows the audience to follow your video with the information.
5)Upload the video to the internet for everyone to access it: When the editing of the video is complete, uploading it to internet where everyone (your audience) can access it. Therefore, when they are in need, they could go online search up the tutorial you made with ease.
The link down below is an example of a tutorial for mobile devices for the Middle-school's OELP passport and visa uploading. Enjoy :)