Servicing you BMW requires you to also reset the service light. The operation for resetting BMW service lights is not the same across the range, so this is the order of operations for any X5 or X6 (E70 or E71).
Insert your remote key into the key slot and press the 'Start Stop' button once without putting your foot on the brake. You should see numerous lights turn on in the dash.
Wait for any warning lights to go out. In some cases, such as a low fuel warning light, you may need to press the 'BC' button on the end of the indicator stalk once to remove them.
Press and hold the black button, which is located on the bottom left of the speedometer (instrument cluster). An exclamation mark will appear in the screen in middle of the speedometer, but keep holding down the button until the next picture appears- then let go.
To cycle through one by one all of the picture options for each service press the black button once. When you arrive at the service that you wish to reset press and hold the black button until the text 'Reset?' is visible under the picture, then let go. Finally press and hold the button again to confirm the reset.
Two service options which may be visible on your dash require resetting to a future date (statutory vehicle inspection and statutory exhaust gas inspection). This is done similarly by pressing singularly to scroll though the numbers and a long press to confirm your selection.