It takes practice to shoot well with the weak hand, but practice is what is needed to become skilled with firearms.
Dry fire drills help alot.
Last year, during a live fire exercise, there were targets behind a garage sized boulder. You had to shoot from both sides. When I got to the left side, I switched hands and shot all the targets weak hand.
One of the other shooters, a gal, said, "Can he do that?"
Well, of course I could. Now she knows.