It is not exactly hard, but you just need to know how to follow instructions. It means you cannot miss one step. Tools, on the other hand, if you have done a headgasket job, you would have most of the tools already. Mr.Kidd have a list of tools, which are about 75% of what I owned, and my hardest job is swapping diff and axles on my S13. The only thing I have in mind is powered tool. This will make your life way better.