So did a DIY on tail light. Changed it from normal bulb to LED.
Things for DIY:
2ft RED Led Strip ( as it is waterproof )
1ft wire ( for simple connections )
Cardboard Piece ( as a base for led's )
First i draw a rough diagram of the tail light on paper then cut led strip as my requirement ( 6led's per strip ). thought to go for 5 strips but then changed my mind and stick to the 4 led strips. After drawing work i took a cardboard piece and cut it in same size of tail light cover and did holes for screws. then mark where to paste those leds on cardboard because that black mark was the place from where leds should glow. After marking, did conncetion of all strips and connect the all -ve together and all +ve togehter. then fit that carboard in cover and connect the light in the place of that bulb and its done.