Lexus units unlocked online from the 16-character ERC number the screen shows itself — nothing has to come out of the dash.
Nothing needs removing. Japanese-built Lexus navigation and audio units show their own serial: press and hold the main button on the unit, switch the parking lights on and off three or four times, then press the one button that lights up on screen.
The screen then shows a 16-character number made of digits and the letters A–F.
Type it in exactly as shown — that is all we need. Lexus and Toyota share the same ERC system, and this is the most heavily confirmed rule we have: seventeen matched pairs, seven of them with owners writing back that the code worked.
If your unit never shows an ERC number, it is an older non-Japanese head unit and we cannot work that format out yet — we will say so rather than guess.
16 characters, digits and A–F. Nothing to remove from the dash:
10184525289BA354