The lense unscrews, but it may be on too tight to unscrew in place. If that is the case, pull the canister down, then try to unscrew again. If that doesn't work keep pulling. There are two spring loaded clips that hold the can in place. Keep pulling at an angle to get one clip out first. It will probably snap your finger, but it only hurts for a little while. Then once you get the can out you can easily unscrew the lense..