I don't think that comics were at the forefront of social change in the 1960's. They were certainly a reflection on the current social situation, but I feel that to say they were at the forefront would imply a more active role. Comics for much of the the 1960's were still influenced by and recovering from the censorship of the 1950's and the Comics Code. They had to work very hard to get away from the increased camp of their images, and it took time for people to shift back to being interested in superheroes. No, comics were more of a tag-a-long for social change than standing proudly at the forefront of it.
It is impossible to mention comics in the 1960's without talking about two publishers: DC and Marvel. DC had an interesting role in the 60's. They were stuck with comics that no one seemed to take seriously for most of the decade, and they were apparently happy with this fact. However, they did re-style and relaunch many of their past characters from the 40's, albeit with an updated look and back story. This reflects the social changes because most of the characters went from leaning more towards fantasy to more towards science fiction. Some examples of this can be seen in the Flash's new costume and the Green Lantern's new back story. This shows how comics were influenced by the increased emphasis on science and math as a result of the Cold War, especially the space race. However, this was the main influence of the 1960's on DC for much of the decade.
Marvel Comics, on the other hand, were much more directly influenced by the times. It was during the 1960's that Marvel developed many of their most famous superheroes for the first time, so there heroes are a product of the age they were written in. Stan Lee helped to change the superhero image, because his heroes were not the images of infallible perfection seen in DC. They got angry. They got upset. They made mistakes. They were much easier to relate to for a generation that felt constrained and misunderstood by society at large. The best example of this is Peter Parker, the secret identity of Spiderman. Marvel tended to create it's comics with much more "fun" than DC, and so they were infused with a greater essence from their creators.
Of course, aside from these changes, the most obvious other influence of the 1960's on comics was in the story lines that were created, but this occurs in every decade. It is in the nature of comics to draw on the state of the world at large for source material. Again, this is seen in the origin stories of many notable Marvel characters; many seem to get their powers from nuclear radiation. The story's also often featured themes difficult to discuss in the 1960's, such as the student protests, the Vietnam War, the civil right's movement, and other issues. However, as I said, this was more out of a desire to reflect the times than to be proactively commenting on social change. Overall, I think that comics weren't really at the forefront of change in the 1960 as much as they were influenced by it.