Hi,
If you have the full version of Vegas, to speed up check this screencast on my site
Adding a Velocity Envelope in Vegas. to go even faster or if you have Sony Movie Studio put your cursor over the end of the media and click and hold Ctrl on your keyboard then drag to the left.
To mask see a screencast I put on Youtube
YouTube - How to use the Bezier Mask tool in Sony Vegas Part 2
Hope this helps.