Open your YUDU Publisher account in a browser window and navigate to your iOS publication folder.
At publication level, go to the Manage Files screen and upload the push notification .p12 file, selecting Security Certificate from the special usage drop down menu.
Head back to the publication folder, select edit next to the folder name to reveal some advanced options.
Next to the entry Security certificate for the APNS select your file from the drop down menu (there should only be 1 file to choose from). Enter the password that you gave the certificate upon creation, in the box below it.