Quick video to show you how to replace bulb behind mirror adjuster on your lexus.
The bulb you'll need is a called a Neo Wedge Bulb and it's size T4 for this application. These are the LEDs that I bought. The fit is a little tight but definitely works.
https://www.amazon.com/gp/product/B00KVXTSEK/ref= ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1