Add kapton/aluminum foil around the part to prevent heating other components, and using an iron or a heatgun, start undoing the sim-reader shield's attachment points from logic board. Gently pry up with tweezers and hold the shield up after it pops out of each attachment point.

Release after solder has solidified, to avoid accidental reattachment. Go around the shield, being careful to not pry too hard until solder has melted, otherwise you will pull pads.

It can be annoying to glue the shield back if too many pads are missing, but none of these outer pads are crucial to the functioning of the SIM reader.

You can also cut the old reader shield into smaller pieces with scissors, to make the removal process easier.