Thanks to Adam’s suggestion about sharpening the plastic card and using alcohol plus the heat gun I easily got to this point. Then I re attached the speakers before dry fitting the new battery.
I did not remove this retaining clip for fear of not getting it plugged in again then just carefully folded it back to clear battery instal
Since I did not remove speakers I skipped this step and went directly to step 17
To reattach bottom case I found it helpful to line fingers up with clips under case should snap easily