As someone who never opened an iphone before, i took the advice and removed Taptic Engine FIRST before the adhesive steps, make your life easier and remove it.
I was nervous not following this guide step-by-step, but as others mentioned I did not have the correct ‘bit’ size to remove the 3 screws circled in ‘red’ in the above diagram. I skipped steps 17, 18, 19 BUT used the ‘tip’ in step 11 to prop the front screen without removing the front display completely and I was still able to replace battery.
Amazing tip Edward, I followed your tip exactly and agree to definitely remove the “TAPTIC”
I just taped down a 8.5 x 11 white piece of paper on my desk and drew a rough image of it, then ‘taped’ the screw I removed to the “image” on paper. It worked just fine. (My first time ever opening an iphone, so give it a shot!)