Hello, did you want to have a small assessment of whether it is possible to change the cylinder head seal with the help of a book like “Now I help myself” or “So wird’s wird’s” yourself? Goes around an 80s with a PM motor. It’s also possible with teeth and tensioning roller. I’ve never done this before, but would already claim to have a certain technical understanding. If necessary, I could still drag my brother who has not done much for cars, but has already done almost everything in the field of two-wheelers. He should definitely get it done or? Wouldn’t it be great if you could say a little bit about it, even if you might need special tools for it! Have, by the way, done the “So we did it”. Have done a bit of research and it is often advised that you have both better. So, can’t you generally say that one of the two is better?