If you google, you'll find the plans for free. Basicly wood or cardboard boxes to prevent light leaking from the sides, and to allow you to adjust the distance of the fresnel (bad spelling I'm sure) lens from the screen of the TV or LCD.
If you look thru google enough, you'll discover there is no 6x lense available. There are 2x and 3x. Staples sells a 2x sheet magnifier for $6, which will work. The "sample" images (at least the ones on ebay) are faked with Photoshop.
Its a neat do-it-yourself project, but thats about it.
If you want to save some time/money... but the sheet magnifier from Staples. Turn the lights off in your computer room, and place it in front of your monitor. As you move it slowly away, you'll see a blurry upside down reflection on the opposite wall. With the box and a better lense, you can slightly improve on the quality of that image.