Unfortunately I have a newer 2.2 model, but if your oil filter is at the top and back of the engine just behind the air filter, like mine, then I got at it by removing thje plastic/rubber engine cover, loosened the large air hose from air filter to turbo, and moved it aside to give more room then used a 27mm socket with a 5 inch extension bar which took my ratchet out of reach of any snags.
Regarding oil quantities, my engine took half a litre less than the recommended 5.5 litres.
Hope this is of some help.
PS. You can also buy a universal joint type socket which lets you get in from various angles for only a few pounds. (Halfords or Amazon)