Twist the bottom counterclockwise to open. That should reveal the battery compartment. Place the AAA battery in its compartment with the positive(plus) terminal facing into the razor, and reverse the case replacement going clockwise until the Hydrp part of the handle is below the blue positive logo and you're ready to use the razor. Adjust the shaving speeds by pressing the yellow button until you're in one of the 3 speeds. To turn it off,repeat the yellow button action until it stops. Good luck! I like it, but am going to try my Hydro 3 blades and see if there's any difference.
Call me left-handed but I kept trying to turn the handle clockwise, then pulling the end along the razor's axis, and attempted to flip it up. Nowhere on the promotional box that housed the razor is their any instructions or illustration for opening and inserting the battery. Goes to show that marketing people too close to the product can overlook the most basic of instructions for the innovation they are introducing. Hand it to a stranger and watch how long it takes to figure out how to open the battery compartment up ... especially for left-handed users! Thanks for enlightening me (us) on this small matter. G.T. Sheffer