This is a simple procedure that anyone can do as long as you have access to axle stands, ramps, car lift etc.
I'm writing this guide to pull together all the tools needed and steps required to carry this out. This was my first time and I spent more time going back and forth looking for sockets etc than actually doing the work!
Required:
torx head screw driver (screws that hold plastic under tray)
14mm socket (bolts that the under tray) 1/2" drive preferred
13mm socket (drain nut on oil filter housing) <<< this might actually be 12mm, I'm going by memory. But you need to use a 1/4" drive, 1/2" socket in same size doesn't fit.
32mm socket (to open the actual filter housing) 1/2" drive required
19mm socket (to open the drain plug on the sump) 1/2" drive
1/2" and 1/4" extender bars (to reach the oil filter housing)
New oil (I used 5w30 fully synthetic)
Oil filter
Container to catch old oil (minimum 5L in size).
Funnel for container (I used a wide mouthed bucket to catch mine so didn't need a funnel)
Old clothes / overalls (the oil WILL splash no matter how careful your are)
Optional:
cable ties to hold back wires and pipes
cardboard or sheets to catch oil spills
rubber or latex gloves
kitchen roll/blue roll
Small hook or pick set (like this: https://www.halfords.com/workshop-tools/garage-equipment/garage-essentials/rolson-4-piece-pick-hook-set)
Scissors
Step 1. Get the car raised up. I used a set of ramps. If the car is cold, let it run for a few minute to heat the oil a little. This will make it flow out faster.
Step 2. Remove the under tray.
Get underneath with your torx screwdriver. The plastic under tray has 3 bolts at the bottom (towards the middle of the car), and 4 at the top (towards the front of the car, 2 on left and 2 on the right).
The torx screws are located along the side of the tray (3 on each side) and 3 along the top (between the 2 sets of bolts on left and right). 9 screws in total. Mine had less as some must have been lost during previous work.
Set the screws safely aside and grab your ratchet and 14mm socket. First, loosen all the bolts and then proceed to remove them. When you're down to the final 2 bolts, use your arm to press up against the weight of the tray, otherwise it might fall and possibly snap at the last bolt or might just hit you instead. Set the bolts aside for later.
Step 3. Replace the oil filter.
The oil filter is located towards the front of the engine, just behind the fan. Look up from underneath and you should see this:
I used cable ties to pull the wires and rubber pipe out of the way so I could get better access.
Then I grabbed my 1/4" ratchet, extender bar and the 12mm or 13mm socket. Put down your cardboard or rags and grab your oil collection container. Open up the small drain bolt in the center and catch all the oil that comes out.
Next grab your 1/2" ratchet, extender bar and 32mm socket. Open up the oil filter casing, catch the oil and then pull out the old filter.
Your new filter should have 2 rubber rings, one tiny and one large. The tiny one is to replace the ring on the drain plug, and the large one replaces the ring on the filter housing. Do this now, and use some kitchen roll to clean them up a bit, especially the treads etc.
I couldn't get the old rubber rings off, so had to use a small hook tool to grab underneath.
Insert your new filter into the housing, then replace the drain plug on the housing. Now screw the housing on using your hand, tighten with the 32mm socket. I didn't use a torque wrench, just went until it was lightly tightened.
IMPORTANT: If you used cable ties to hold back wires and pipes, grab some scissors and cut the cables ties now. I forgot, finished the job and replaced the under tray and then had to take it off again! The cable ties / wires etc could possibly foul the radiator fan and cause some trouble.
Step 4. Drain the old oil
Pop your bonnet and open the oil filler cap.
Grab your cardboard or rags, 1/2" ratchet, 19mm socket, and container for the old oil, slide back towards the middle of the car to find the sump and drain plug. You should this:
Loosen the bolt with the socket and then open it the rest of the way by hand, have your container ready as this is gonna fly out fast.
Once all the oil has drained, replace the sump bolt and tighten with the ratchet (not super tight!)
Dispose of the waste oil at your local recycling center.
Step 5. Replace the under tray and fill with new oil.
I put the bolts in first, by hand and then tightened them up with the 14mm socket. Then put the screws back in.
Now fill up with new oil. I think the 2.0L Octavia TDI takes 4.6L of oil, but don't quote me on that. I bought a 5L of oil, filled it with 4L, let it sit for a few minutes and checked the dip stick, then topped up a little, let it sit, checked the dip stick again.
I think I used just under 4.5L.
Don't forget to replace the oil filler cap once you've filled it with new oil.
And you're done! Put away the tools, get the car off the ramps / axle stands / whatever and get cleaned up. If I've missed anything out or made any grave mistakes, let me know. I changed my oil and filter yesterday. Was going to do the fuel filter too but had got the wrong one. Will get it changed next week.