Post Thumbnail / Post image: size and float

First of all i am sorry for my english, but i will try to explain my question: I am using catch everest pro theme and the function with the featured page slider (via Post Thumbnail / Post image >> actual page image ??) on the Homepage. That´s great :-) Now I would like to change the size and the float of the image in the actual page. it is very big and on the top of the page and only beneath begins the text... I would like to make the image smaller and with text float left. How can I do ist – without changing the page slider on the Homepage? THX in advance!