After I updated k2 2.6.5, my k2 camera slideshow is missing on the frontend. I keep seeing ppl saying I just need to roll back to k2 2.5.7 but I have no idea how to do this, as I'm still new to both joomla & k2....

Suggestions?

You need to update the package. I had the same problem, and the people of entheosweb told me that solution.

Good luck.