Yesterday I updated my site to K2 2.4.1.  I just noticed that all the changes I made to the k2.css have now been overwritten.  How can I guard against this with future K2 upgrades?Thanks!Andy

take a look.
community.getk2.org/forum/topics/k2-template-override-package?commentId=3536014%3AComment%3A82449&xg_source=activity

Thanks so much for your response. Not exactly clear from the article where/what I'm supposed to change once these have been unzipped.

Copy the files to /templates/yourjoomlatemplate/html/com_k2/templates/default

like it is in components

This is the first point where k2 looks if a k2 template exist - if not it uses the template in components/com_k2

If you install a k2 patch your modified template won't be overwritten.

Awesome, thank you for the clarification.