You can get copies of the original IH service manuals from your local Case/IH dealer, or on line from http://www.binderbooks.com
You can also get aftermarket repair manuals printed by I &T at most places that sell tractor parts and implements, such as TDC. ,etc. The I&T manuals assume you are an experienced mechanic, and not quite as comprehensive as the IH manuals, but they usually cover more than one model, such as one manual may cover A,Super A C, H, M, etc.
I have pretty limited experience with Super A, but the front tranny seal will require splitting at the front of the tranny, so you will need to wedge front axle to keep from tilting, and support both halves. I believe the tranny input shaft on a SA has a universal right at the front of the tranny, so you do not have to deal with the long shaft like on a cub. I may be wrong on that point. It will take someone who has experience and the right equipment half a day or a little more to change that front transmission seal.