TV Grip Practice

Making a grip change is no easy proposition. The solution is to place your hands in the new position at home while watching TV and practice.  You can do this sitting down and swinging the club up and down in line with your trail shoulder. 
Make sure you get your hands on the club correctly.  Your target hand makes a cocking action so be sure to get both your heel pad and wrist joint on top of the handle.  Your trail hand bends and should face the same direction as your clubface. 
Practicing this for few minutes every evening during the news will help acclimate your hands to this new feel position.