I'm going to assume you have the low cluster which only has the trip odometer reset button on the left side...see instructions below. If you have the nav screen & high cluster...then do NOT use these instructions...the high cluster uses different instructions.
Below are the instructions to unlock the low cluster along with brief descriptions of what info they reveal & how to read what you see in the low cluster's limited display for alpha numeric data. If you are a visual learner...there are multiple videos on YouTube that covers this. Just be sure to search for low cluster or base cluster. If you see a BMW video showing 2 buttons & the 20 digit alpha numeric display where you have to enter the sum of the last 5 digits of your VIN...skip it...that's the high cluster: