Hello,
You're suffering from a 'hot pixel' (where the red, green and blue subpixels remain on, creating a constantly white pixel). A dead pixel is when it appears black (when the red, green and blue subpixels remain off).
What brand LCD HDTV is it because manufacturer's have different policies on warranties regarding defective pixels. Dunno about whether the retailer will replace it for you but chances are they will anyway. Personally, I'd go get a refund / replacement. Sure it's a hassle, but I'd feel more satisfied.
As well as the method of applying pressure, another method is
RGB cycling, which involves cycling the red, green, and blue colours of each pixel at a rapid rate, over a long period of time. If it were a computer LCD TFT monitor, then you would have been able to use a java application (such as
JScreenFix) to do the cycling.
If your LCD HDTV has DVI input, and your computer's graphic's card has DVI output, then you could hook your LCD HDTV to your PC using a DVI cable and run the java app full screen on the display.
JScreenFix also offer an RGB cycling video in various formats which include VCD and DVD images. So, if you have the resources, you could burn the RGB cycling video onto DVD, and play it on a DVD player hooked up to your LCD HDTV.
If you don't have java, or don't like it, there are applications which do the same job:
DPS -> Freeware -> DPT
UDPixel - udpix.free.fr