Changing soil vent AAV

[Maxima88x]

I have an AAV connected to the soil pipe. The model is ventapipe vp50p which is leaking and causing foul smells. It needs to be replaced but I can't manage to pull out the old AAV from the soil pipe. It is a push fit connection (so not welded) but no amount of pulling or twisting budges it. Is there any trick of the trade in removing it? Thanks in advance.

 

[WC1]

Good quality fine tooth saw.

 

[ShaunCorbs]

Pull and wiggle will take some pulling