TouringPlans.com has a "Room Request" feature that helps you request a great room at a Walt Disney World Resort Hotel. (Note that you must have a Walt Disney World TouringPlans.com subscription that is valid on your check-in date in order to use this tool.)
Although the process is not hard, it involves several steps. You have to create a "trip" on your TouringPlans.com dashboard, select your hotel for that trip, find a desirable room in our "Room Finder" database and request it, and finally fill out details that will be used in the request that we'll send to Dsiney on your behalf.
To simplify things for you, we have an overview of the process on our YouTube channel. Please see the following two videos: