Sorry the resurrect old topic but I ran into the same issue, can't reach the oil filter and can't even remove exhaust holder L shape part either to get a better approach, as the screws around for were completely stuck, plus the oil filter hasnt got a socket and on it, so I have to just leave the oil filter change next time..not great but I haven't got time to order a removal tool.I presume you've a petrol A2?
It's a bit tight from above, and not much better from below, but take the undertray off and take a look.
30mm socket or wrench should crack the joint, then spin it off.
Lube the new filter's seal with a smear of fresh engine oil and tighten the new filter to 20Nm.
Cheers
Jeff