I WILL TRY THAT THANKS

I HAVE DIABLOSPORT PREDATOR GM GAS 99-02 BIOS V-6.01 ON MY 2000 CHEVROLET SILVERADO Z71 5.3.
MY QUESTION IS HOW CAN I GET THE SHIFT PRESSURE DOWN ON MY TRANSMISSION? RIGHT KNOW I HAVE THE PERFORMANCE 93 TUNE ON MY TRUCK AND THE TRANSMISSION SHIFTS REALLY HARD AND I CAN'T SEEM TO GET IT TONED DOWN ...