Things You'll Need
Instructions
Log onto your YouTube account.
Click the "Upload" button on your YouTube account page. This will open up a drop-down menu, from which you'll select "Video File."
Select "Upload Video" and find your saved replay -- either in your game's appropriate file or wherever you saved the file using FRAPS -- and wait for the blue upload bar to fill.
Wait for the YouTube staff to accept your video once it's uploaded. You'll know it's accepted when the label next to your uploaded video says "Live" instead of "Processing."