Step one… Remove bulb, break the outer glass… remove all glass, be sure to NOT damage or break off the two filament holder wires. Take the base off the LED light, and cut the flat piece off, and slide the base cap "bottom" back on. This helps hold the circuit board in place better. Solder the two leads from the LED Light to the two Filament holder wires. I recommend bending the filament wires down so the light doesn’t stick out so far, or make the light too long. You still want to use some of the reflector in the light housing.
Make sure everything is in place and put the bulb back in.. It’s as simple as that. It makes a HUGE difference. Each of these LED super bright bulbs uses 2.5 watts, where the incandescent used 5 watts each. This allows extra wattage to power the soon to be added tail light. You can definitely see the difference.