It might be tricky the first time you do it, but once you know how to do it, it won't be difficult anymore. Open chrome, and the auto typer you downloaded. Resize chrome and the auto typer so they are side by side as shown in the picture below. When resizing the auto typer, make sure you are able to see the play button at the top right (we will be usin gthat button to make the auto typer type). On the auto typer, next to where it says 'setMySpeed to', type your speed there.
