Gear Box Cover and oil Level plug bolt is indicated, seen to the centre right of the picture. Drain plug to the right. The return pipe from the turbo to the intercooler can be seen with it's new coat of paint. The engine oil filter is on the left. 

To remove the drain and filler plugs requires a 7mm square drain plug spanner. These can be obtained from Halfords. Without the correct tool it can be very difficult to remove these bolts, as I found!

The gear box takes about 2.75Litres of oil. I found I could only fill 2.5litres of oil. Possibly due to my not being able to drain completely from a gear box not level. After running the van, I did another check and added about a third of a litre.

When you remove both plugs, you will find the drain plug has a magnetic tip. Ensure the correct plugs are re-installed into their locations.  If the magnetic tip has a cluster of heavy bits then it could be a problem which might need investigation.