Removal of the battery IS completely necessary IF you are truly trying to get your power button to work again. This guide completely leaves out the portion where you have to replace the power/volume/mu
te ribbon. If your power button is not responsive, you MUST replace this ribbon. With that being said, the battery sits on top of the ribbon and must be removed. I found it less likely to cause damage to the phone if you remove the logic board first, THEN remove the battery. Reason for this is that you'll have much more room to work with and you won't risk breaking anything on the logic board as you pry out the battery. Also use a guitar pick to help break away some of the adhesive. I truly think this guide should swap the steps for logic board removal and battery removal.