First, navigate to the publication you wish to move within your YUDU Publisher account.
Click into the publication as if you were to edit it, then along the toolbar at the top showing the location of your publication, you will now see a Move button as below:
You will be presented with a collapsing folder structure of your account. Expand/open the folders using the + symbol, then click the name of the folder you wish to move the publication to and the process will be complete.