This instruction will show you guide on how to change the engine oil at home for Mercedes GLK.
This is same topic article for your further reference:
Use a jack underneath to lift both the wheels off the floor (you can also do the oil change on the ground)
Unlock all the bolts then take the engine cover off
Oil drain is right there , unlock the 13mm nuts
Put a vessel under the oil drain, Leave to drain while changing oil filter
Take off the engine cover,then remove oil filter housing
Replace three O-rings and filter
Put it back in position
More cases about Benz, please refer to Benz Trouble Repair.