At the end of the game, where you would normally go to a view a replay, you can select "highlights"

Just click on that, and let it play out. When it is all done, hold the "share" button on the controller, then hit SQUARE to save the video. It will save aprox the last 5 minutes of gameplay.

Then go to capture gallery, and you can trim the video down to where it just shows the highlights. Then I upload it to my youtube channel.

Once it is uploaded, I open the video, click on SHARE, then EMBED. It gives a code to copy. Post that code into the forum.....and your video will be displayed.