Connect them to your Neopixel/RGB-Port of your printer mainboard - make sure you have a current mainboard like Fysetc Spider or SKR 1.4/Octopus/Octopus Pro by Bigtreetech.
If you already used the Neopixel/RGB-Port of your printer mainboard - no problem! You can connect DOUT of your existing strip to DIN of these LEDs. You just have to ensure that you have the same LED type - if your existing strip has RGB Neopixels, use WS2812B. If your existing strip has RGBW Neopixels, use SK6812.
Important! The data signal can be degraded if you run it over a long wire (signal reflections on transmission lines). If your LEDs don't show the desired colors or switch colors at random please try a very short cable to the mainboard first to ensure your wiring is correct. Then put the 100-120 Ohm resistor in-line with your DIN wire as close to the mainboard: DIN Mainboard -> 100-120 Ohm resistor -> long wire -> Neopixel DIN.