How do you change a headlight 2005 Volvo s80 t6?

It will vary depending on if you have HID lighting or Halogen Lighting which you did not include in your question. 2005 Volvo S80 headlight bulb general replacement procedure: Purchase the correct replacement headlight bulb(s) first, before disassembling the vehicle. See sources and related links below for replacement bulb information. Then consult your owner's manual for the headlight bulb replacement procedure. As simple as it sounds, the owner's manual is the best place to start for bulb replacement instructions and illustrations. You may want to consider replacing both left and right at the same time in order to keep brightness and color equal (optional).