Firstly go through separate battery removal guide. insert straightend paper clip into SIM card holder (arrow) and eject and remove it.

remove 8 screws shown, incl, metal plate over charging connector and the sim card holder.

Wireless LAN RF cables can be left in place.

disconnect all other connectors from mainboard (and tape that fixes the connectors and Flex connectors)

Tip : Take note of magnet location (square) and orientation in case it dislodges. use marker if needed.