Author's note: I have no intention of retaking these photos as I do not have my 1697 anymore (and avoid them when possible). I can do this with one hand, but using a pry tool in the area marked in orange makes this easier.

With the screws removed from the back, flip the controller to the front. Remove the front plastic cover.

With the front plastic cover removed, remove the back shell. A plastic pry tool can be used if it is easier.

Remove the shell once the battery tabs are released.