Hi mate, Pirtek sell rubber reducers. Mine was a 4" to 3" reducer and I'm sure you could get 3" to 2".
You'll to have to get a short piece of two inch pipe (metal or plastic). Slide that into the flexi pipe (clamp) and slide the other end inside the 2" side of the reducer and clamp.
Then run a 3" pipe (metal or plastic) out the other side of the reducer (clamp) and into the elbow and (clamp).
Below is the reducer I used for the 3" outlet on the GU air filter to the 4" stainless steel on the snorkel.
I would try a Pirtek store for that or Purple Pig or a truck pasrts shop or something like that.