Complex sentence: Puigblanque extended it, by linking it to another route nearby, but the extension did not increase the grade, as it is much easier than the crux, which is in the first part of the route.
Split into simpler sentences: Puigblanque extended it, by linking it to another route nearby. However, Puigblanque's extension did not increase the grade, as it is much easier than the crux, which is in the first part of the route.