Well, juste put your pointer at the exact beginning or end of your video in the track viwer. Your arrow should change into a horizontal cursor composed of 2 arrows which should allow you to strech or minimize the size of your video ie -> its duration :)
This is asked a lot. You can do a search to get details. The short answer is:
1. You can press and hold the Ctrl key while dragging the edge of an event.
2. You can right click on an event, select Properties, and then Playback rate.
3. You can click on Insert, Video Envelopes, Event Velocity to add a velocity envelope. This will add a horizontal line to the event. Drag it up to speed up; drage it down to slow down. If you drag it down far enough, the event will reverse (play backwards). You can right click and add points, and then drag the points up and down. This lets you change the speed as the video is playing (i.e., gradually speed up or slow down the clip).