A few thousand deliveries in the nets not worrying about regression to worse shots while you work on it will probably get you there. I believe there is no such thing as too old to learn technique. I've learned new technique to compensate for serious injury completely and permanently altering my balance - so I did it because I had no choice which engenders a certain commitment to the new thing. I'm now a rubbish bat but clearly, at least according to the scorebook, less rubbish than I was! Do you have much to lose? Hope you have an enjoyable and successful season either way.