An oil change on a modern GTI (EA888) is an easy DIY and the single most important maintenance you'll do — every ~5k miles with VW 502 00 oil.
How I do it:
- Warm the engine, raise and support the front (or use ramps), and remove the undertray.
- Drain — the sump plug's on the aluminium pan; I use a new crush washer and torque to spec (~30 Nm — don't overtighten the alloy pan).
- Filter — the EA888 uses a cartridge filter in a housing on top; unscrew the cap (often 32 mm), fit the new element and cap O-ring, torque the cap (~25 Nm).
- Fill with the correct grade and quantity (GTI Fluids Capacities), run it, check for leaks, recheck the level.
- Reset the service reminder (VCDS/OBDeleven or the dash menu).
What I watch: don't overtighten the plug in the alloy pan; and always replace the cap O-ring.
So cartridge filter on top, alloy plug with a new washer, correct 502 00 oil, reset the reminder. See Spark Plug Change DIY.
For this you'll want VW 502 00 oil, the cartridge filter and O-ring, and a fresh sump crush washer — I've put them below.