• original flame m0dul
• 1x RGB LED
• 2x 100K SMD Resistors
• a few centimeters hookup wire (german: Fädeldraht)
• soldering equipment

Source LRTB G6TG RGB MultiLED LED Datasheet

• unscrew the acrylic flame
• unsolder the original one-color LED

• solder the RGB LED contacts A1 and C1 to the original solder pads from the one-color LED
• solder one hookup wire to each contact C2 and C3 on your RGB LED
• connect A2 and A3 together and solder one hookup wire to it

• solder two 100K Resistors to the board
• connect the two wires from C2 and C3 to the board
• connect the third wire to VCC