Once you have created a channel, you can start to add existing videos to it using the Add Existing Video option per channel.
Step 1. Click on the Channels header navigation link.
Step 2. From within the channel list, click the option to Add Existing Video.
Step 3. You will be taken to that channel's Video List tab and you will be shown a list of available videos you can then attach to the channel. Click on the video's check box to select it.
Step 4. Click Add to add your selected videos to your channel.
Step 5. You should now see your videos added to your channel.