Heat the tape areas with a hair dryer. Simple and works well. Only need a minute or two doing the heating.
Definitely remove the Taptic Engine. Gives an easier angle to remove the strips under the battery. Lift the phone bottom about 30 degrees and heat the bottom of the phone with the hair dryer for about 30 seconds. Then heat the tabs on the face of the battery for about 20 seconds to soften them. Pull back the first tab with the tweezers to loosen all you can, and pull with a full width hold using the tweezers until you get about 2 inches of tape loose. A slight side to side motion helps to dislodge the tape. Wind the tape around a pen or pencil and keep pulling slowly to not rip the tape and wind as you go. A gentle side to side motion works well to start with, then just keep pulling straight back. You want the tape flat and wide. When the tape starts to narrow you are almost done. Seems like you have wound about 12” - 16” onto the pen. Then do the same for the 2nd strip. Remember to hold the battery in place as you near the end of the 2nd strip as the battery will be loose when you reach the end.
I skipped 17 to 22 as I was not redoing the perimeter glue. Worked well for me, except the phone will not be water proof.
For removing screws, I used a piece of paper and sketched the screw locations and screw sizes in the appropriate pattern for each step I was working on removing screws. I folded clear packing tape in a loop so some sticky area was on top for each screw so they did not fly away when the hair dryer was on or in case I knocked the paper while working beside it. This kept all the screws in an easy pattern with descriptions for later install. Worked slick.
I used a full beer can and 2 elastic bands to hold the face at 90 degrees. One elastic at the top and one at the bottom keeps the face still at 90 degrees. This allows you to work on the phone easily. I did not remove the face totally to redo the perimeter glue as I have never dropped my phone in the water over the “long” time I have had it.
Clean the glass screen first with eye glass cleaner wipes (alcohol). Hair dryer on hot with low air speed works excellent. Aim the heat at 45 degrees (phone face up) and move around the perimeter for about 1 minute. The edges should be hot enough to barely touch without burning your figures. This seems to get the glue hot enough at the edges for easy removal. Warm the glass face a bit and also warm the suction cup, this makes the suction a lot better and the suction cup won’t come off like it will if the face and suction cup are cold. Later when removing the battery, heat the bottom with the hair dryer for about 30 seconds and the top of the bottom of the battery where the 2 tabs are for the tape behind the battery. This makes for simple removal of the battery tape under it.