I ordered them on Amazon. Most of the bulbs are 12v, so you'll want to find 12v LEDs to replace the 12v bulbs. You can be specific to 3mm or 5mm , but in most cases it doesn't matter, I used 3mm for all of them. The problem you'll find is when you run into a bulb that is actually an led. Those were only provided 2v or so. They do this by using an inline resistor on the circuit board. I backtracked the trace from one leg of the led to find the resistor, removed it and replaced it with a wire jumper. Now you can use a 12v led and will have a full 12v source. You could also replace with a regular led, but I bought a pack of 50 12v LED's so I didn't want to buy more.
You'll want to take the panels apart and then plug them back into the truck, turn the truck on and use a meter to identify the positive terminal of the bulbs before you install the new LEDs. Make sure you know what the positive terminal of your led is so you don't have to pull them and flip them afterwards.
I've done all the gauges on the dash as well as the doors switch panels, so if you have any questions just message me.