Using a screwdriver, remove 7 Phillips #00 screws from the front panel of the camera chassis.
The D5100 is held together by a large number of screws of varying lengths, so be very careful to keep track of all your fasteners!
Carefully peel back the rubber hand grip, which is attached to the camera body with strong adhesive.
Remove the two Phillips #00 screws hidden beneath the hand grip.
One screw is not shown in this image, although its location is circled: it is hidden in the upper portion of the hand grip, with its head facing downward.
Open the battery compartment and remove the battery (not shown here).
Remove the Phillips #00 screw hidden deep within the compartment.
You may need to use a screwdriver extender to accomplish this.
Firmly separate the front panel from the main camera body. You will feel some resistance since the chassis parts fit tightly together; this is to be expected.