The old tutorial was taken down a while back because it was based on one of the earlier versions of the toolkit. I’ve published a new tutorial on how to start out with a new level. You can check it out here: Top Down Stealth Toolkit Tutorial: How to create a new level
As mentioned in the message, all the old tutorials will be ported over to the blog & updated to the latest version over the next few days. Let me know if you need help with anything in particular.