Get the fan or fans you are going to use. You can get them out of a nonworking DVD players or computers they will be 12v or you can get 5v ones off of things that plug into a USB port.
the 5v is the easiest way if your TV has a USB port
Go on google and find a 3D printing company that lets you order a print from them. or if you are lucky to have a 3D printer go to the software and bring up the sketch pad
now if if you have
12v fans you will need a 12v output transformer
5v fans get a USB cable -- this is the easiest way if your TV has a USB port
you need some small but splice connectors
now take and measure each fan and put it in the program and then take and add some little tabs that will allow you to sit it in the air vents on the TV.and make sure the fan blades will clear so that it does not stop them from turning.
now send the order and pay now wait for them to arrive.
now they have arrived take and see how the fans fit if everything is good, get your power source.
now strip your wires put red in one end of the but splice and take the black and do the same.
12v -- if this is what you are using the black will have a white line on it.
5v--- red to red black to black
now put them in the but splices crimp them down now test if it or they spin fine mount them the way you want air in or air out.
if you have more than one put one in and one out.
now test and make sure they stay now you can extend the life of you TV.