Heated seat indicator lamp replacement

[EChem]

My 2002 S80 has heated front seats. The pushbuttons that control each of them has 2 orange indicator lights, each indicating when on that the seat or backrest are being heated. One of the lights is not coming on, I assume the lamp needs replacing. 2 questions for any that may know:

1. What is the part or model number of these bulbs?

2. How do you access them for replacement?

Thanks.