LED backlight install?

You do it the same way but they do make LED's that you don't have to worry about the polarity like he goes on about. Just plug in and make sure they have a good connection to light.

Many of the bulbs in my display were T10 / 194 size bulbs and replaced with:
https://www.amazon.com/dp/B00MAG6RMM/?tag=fabo03-20

Oh, forgot to add that if you change out your turn signal bulbs, you need to get a turn signal flasher can specifically for LED's or they will flash super fast (or not at all). LED's use a lot less power and the flashers in older vehicles are made for more of a power draw.