Yoko theme header image

I have a Yoko theme in my website, quite a simple one, and I would like to make a small change:
I would like to keep the header image of the main page, but change it in all the other pages, because it is too high and ennoying for readers of blog posts..etc.
How can I do that?
Moreover, How can I insert a slide show or something else instead of the header image on the main page?