Help?! I Changed My Speedometer Readout From Mph To Kph.. How Do I

[Is_fast]

I have a 2011 IS-F -I have no idea how I managed to change the readout - can anyone tell me how to change my speedometer digital readout back to mph?

[1990LS400]

See page 301 of the attached manual section: http://drivers.lexus.com/t3Portal/document/omnav/OM53A02U/pdf/11.pdf

[Is_fast]

Thank you - I appreciate the response, by your answer, I need to clarify..

I was resetting the maintenance indicator light - by depressing the start button twice while depressing the odometer trip rest button - I reset the indicator light, but also changed the digital speedometer readout from MPH to KPH.. There must be a sequence of depressing these buttons to change it back? I have spoken to every maintenance tech at my local Lexus dealer and no one can find this. I reiterate- It is the digital speedometer readout on the instrument panel that changed, not in the navigational system. I'm not sure how to post a photo.. Any ideas?

[1990LS400]

How to toggle the digital speedometer in the instrument cluster between mph and kph is explained on page 148 of the 2009 IS-F owners manual: http://drivers.lexus.com/t3Portal/document/om/OM53893U/pdf/sec_02-02.pdf