The aluminium cover within the V involves removing the injectors, the PAS pump, the intake plenum. a bit involved if spanners aren't your forte, but not difficult. Just buy a new gasket from Audi, and replace.
The dipstick tube is easy, there's a bolt that holds the tube in place. Unbolt, and the dipstick tube just pulls out. the O-ring is then slid off, and a new one fitted.