Navigate to the folder you want to save the video to.
Drag and drop your video to the picture in the middle of the screen or click the "or click here to choose files".
Save.
Navigate to the content pages and from there to the content page you wish to insert your video.
Go to the Main text editor and click the cog icon labeled "Insert Macro" near the top right.
This opens up a panel to the right which will allow you to navigate your media to the video you want to insert.
Once you find your video file, you can optionally give it a label also in the expanded panel. If you wish to finish, simply click the submit button at the bottom right.