Flat panel televisions often come with bases which you can use to set them atop stands. However, if you want to wall mount a set, you must first remove its stand. Taking the stand off requires only simple tools, and perhaps an assistant to lift the unit from the base. Once you remove the base, you can mount the flat panel to the wall as you see fit.
Turn the television so you can access the rear of the set. Locate the screws holding the stand's posts in place (commonly four Phillips screws).
Remove the Philips screws from the base with the Philips screwdriver.
Lift the set straight up off of the base to complete the separation. A tight-fitting base may cling to the set even without the screws, in which case you'll need an assistant to help pull it off while you lift the television.