This page will show you how to install the MINI Cooper R56 LED Side Marker Indicator Lights (75-053)
Step 1: Push the original side marker all the way towards to the back (towards the taillight direction) and at the same time use a pryer to pop out the lamp.
Step 2: Once the side marker lamp is out, unplug it to remove the incandescent bulb.
Step 3: Install back with LED side markers, and install back the adapter too.
Step 4: Install back the LED side markers, double check the direction.