Originally Posted by antmeeks

You can't do it on the unit itself, but it's still super-simple.

Upload the course to your Garmin Connect account then select the course and click on the edit button (pencil icon) in the top right corner.

On the right-hand side of the screen, you'll see a panel that includes a field labeled "Speed".

Type in your desired increase, hit return and then click the "Save" button at the top of the screen.

Next, with your Edge still plugged in, click on the button "Send To Device".

That's it. The next time you ride that course, you'll be riding against the VP at your new speed.