It is possible to replace the battery without performing steps 5 and 6. It requires someone or something to hold the screen upright while you work on the battery. Just make sure that the screen doesn't fall.
To open the system the way it is shown in step 5, the system must be turned around. The HP logo must be in the back and the camera in the front. If you open on the HP logo end, you risk damaging the screen cable.