I sorry for my delay.
This is a tutorial to change the font ,text and and all style, you can reference:
www.joomlaux.com/blog/item/43-tutorial-h...jux-testimonial.html
You can wait the for new version jux_Testimonial:
This is conflict between bootstrap 2 and boothstrap 3 of Joomla. We are fixing this issue, and the newest version will be update in 16 or 17 November. The new version will advoid this conflict. Could you wait for us until that day?
Thank you for feedback. If you have other question, you can replay at here.