lol I'm quite attached to Yew as well. ;)
Oh, are you saying you can't open the file? It's a 7zip archive file (like a .zip file), so you need to unzip it with 7zip:
https://www.7-zip.org/
I know the supplier is reliable because I've already gotten my product from him and spoken to others who have gotten it from him as well. The Peaceful Pill Handbook is a great resource that weeds out bad suppliers. For example, for several years there were Chinese suppliers selling pentobarbital powder, and the doctor who wrote the PPH regularly tested their product for purity. Unfortunately, all of the Chinese suppliers are no longer around, leaving only one supplier left, for now at least.