Chuck removal DC970 Dewalt 18 volt cordless

I used a Torx T-20 screwdriver to remove the Left Hand chuck screw. I then made sure that the drill was in low gear and in the drill setting. Use the largest allen wrench that you can tighten in the chuck. Insert the short end of the allen wrench into the chuck and tighten up the chuck. Lay the drill on its side , then strike the long end of the allen wrench with a hammer to unscrew it from the spindle. Once the chuck is removed, screw the new chuck on the drill spindle tight. Then screw in the Left Hand chuck screw. And you're done!