Hello,
First, click on the below link in order to identify board. You will also find the part number and other information listed below the image of the T-con board. Also, if you wish to order, you can order direct from the link.
http://stores.orlandopc.net/-strse-3084/MAGNAVOX-T-dsh-CON-BOARD-1320WA01CCAA/Detail.bokNote the TV stores electric current. So if you just turned off the TV, wait a while (30mins) before opening the back cover.
Now that you know the board that you are looking for, turn off the TV. Get a set of philips screw driver. Look at the back of the TV. Amongst the set of screw driver, look for the one that can fit into the screws holding the TV back cover, then unscrew all the screws.
You will find panels, inside the TV. Unscrew all screws holding the panel in order to get to the T-con board.
Take your time to study how the panels and board in the TV are fitted in, so that you can get them off easily.
Lastly, use a camera to snap the of the TV and each step you take as to removing any screw or disconnecting wires from the panel, so that it will be easy to fit them back to their right position in case you forget.
I hope the above is clear.
Regards.