I can follow and understand up to step 11.

Steps 12 and 13 loose me, why would one need to remove the metal protection lid / shield? There does not seem to be any screws covered by the lids that need to be removed.

one would need to unclip the screen from the motherboard the lead off board from the wireless card to aerial and unscrew the remaining motherboard screws at least before you could remove the motherboard to access the screen to replace it.