If you want to reset the service oil on a Peugeot Partner or a Citroen Berlingo you have to follow these 4 steps from the video below:
STEP 1: press and hold the left button from the instrument panel
STEP 2: turn the key on second position
Keep pushing the button until the count on display reaches to 0
STEP3: release the button
STEP 4: turn off the key
If you want to check that you reset the service oil correctly, turn the key back on and check if the key symbol has dissapeared from display and, also, if there’s a specific number of kilometers to the next service.