Once you select a winner for your contest, you will be directed to the Contest Handover page. This is the part where the winning designer hands over the ownership of the design of their files to you.
They should provide you with all the files for the design you have chosen as the winning entry of your contest. They will be able to upload and submit the files through the Handover page, and you will be able to view and review them before accepting. If you need the designer to make any changes or minor adjustments to the design, this would be the time to request it from them.
You can communicate with the winning designer through the message board right below the list of files on the Contest Handover page.
Once you accept and download the files, they are yours. The Handover process is complete and the winning designer gets their prize money.