Welcome to the tiny world of fake skateboarding. Here is a quick introductory guide for how things are done around here.

1. Learn to film. You may have been playing the games for centuries; however, that is no excuse for bad filming. Here are a couple of guides to help you out with the basics.
Innout's guide
POOOPOOOirwin's guide
I'm not saying you have to film like those guys, find your own style. Those are merely to show you how to control the adv. free cam.

2. Get a converter for your clips that you retrieve from your skate reel. This is basic shit, really.
Here's a few suggestions: (anyone feel free to chip in)
FLV to AVI MPEG WMV 3GP MP4 iPod Converter
Prism
Convert your .flv to a format you are familiar with. MPEG, MP4, WMW are some of the more common ones. Convert them either to the same size as the original .flv (1152x656) or HD if you feel fancy.

3. Acquire video editing software. If you are cheap; legal; lazy or plain retarded, there usually comes some sort of basic software with your operating system (Windows Movie Maker, iMovie etc.). Preferably you'd obtain something a little more advanced because come on, who doesn't like to make sweet animated transitions and hyper-cool radial blurs?
Final Cut Pro
Sony Vegas
Adobe Premiere
These are hella expensive. Is there any possible way you might get a hold of them for free? Go figure.

4. Edit your converted clips in your fancy video editor, use some cool effects (FILM BURNS ARE SO HOT RIGHT NOW) and a semi-gay upbeat song. Upload that shit to Youmeo or whatever. AND FINALLY, submit it here!

This is all I can think of right now. Help me out fellas!