Yes, you don't need to do this step, but you SHOULD gently pull the little loop that is to the right of the yellow box -- separates the trackpad wires from the board. Compare the picture in 14 with the picture in 15 and you'll see the technician did this.
If you don't do step 14 (and you really DON'T need to), then know that you're not going to be able to remove completely the upper case from the lower. It will be attached by the black/red wires and the gray wires (see my comment in step 14, too, about detaching the wires that connect with the trackpad). I could not lean the upper case against the screen -- my wires were not long enough, I guess -- but since both sets of attached wires (skipping step 14) are on the same side, you can tip it up and hold it whilst you remove the hard drive. Yes, be patient in doing this step. I broke a guitar pick doing this, so you can apply some force, but do so gently. In the end, I'm not sure what I did to get the non-battery side separated, but just kept wiggling it and applying some force near the trackpad. It popped, and I immediately stopped putting on pressure to ensure I did not pull the upper case completely off (separating the wires/connectors referenced in step 14).