The battery is still connected at this stage so, yes, avoid metal tools.
Once the outer frame was mostly unclipped with the opening tool, I found the ifixit triangle plastic picks useful. As well as clips around the 4 edges there are maybe 4 more clips in the centre of the back cover that are a challenge.
Make sure the display screen and logic boards and battery all come out in one bundle, just leaving a bare plastic back shell. Others have reported that if you separate the screen from the boards you’ll invariably break a ribbon cable and lose touch sensitivity.
Lifting the old connector out was easy, fitting the new one seemed to need very careful alignment.
Original battery was a very snug fit in its space and the triangle pick tool helped. The replacement battery was 2mm narrower so much easier. The pull tab is strong, and needs to be strong.