Want to customize 'Read More' link button

Hi! I am using the SKT Yogi Lite theme and on the homepage there is a slider and these Read More boxes that you can link to whatever and I want to change this text to “Class Schedule”. I have read like everything out there and the code snippets, and plug ins are not working for me. I don’t think the solutions given are pertaining to my exact problem but instead to people wanting to put writing excerpts in and then add a read more button at the end. So I am not sure how to modify this in the theme. I have looked everywhere in the edit themes section and cannot find how to change this. Any help is greatly appreciated.