Just right-click on the video object you want to manipulate (in timeline mode) and choose "Video effects" from the context menu that will come up. That's one way to bring up the big video effects dialog. There you can find the play speed slider, among many other things. Just speed it up to 2x and confirm the dialog. If you want to go even beyond 2x, make sure to ungroup audio and video track of your video clip first.

Keep in mind that all editing in Movie Edit Pro/Video Deluxe is purely virtual and doesn't change anything in your source file. If you want an actual video file with the sped-up version of the clip, you will have to render it again, i.e. using the "Export movie" function in the "File" menu to create a new video file that reflects your changes.

I hope this helps.