How can I un-install 3.9?

How can I go back one step. I updated to 3.9 and I don’t like it at all. I have 3 websites all running the exact same theme and plugins. All 3 look totally different when writing a post. One blog has hardly no options for writing, one has a little more, and the third one has everything the old version had. How do I get the other two to update properly and show all the options for writing?