Add solder to the pins before installing the new SIM socket.

The socket will have 8 signal pins on the side where the card is inserted, several pads for shielding, and two pads at the rear to detect whether the SIM is inserted.

To make the socket more stable, place the new socket on the board and solder at one shield edge first.

Solder the eight signal pins at PCB board edge. If you accidentally bridge some of the pins, don't panic. Use a solder wick to remove excess solder.

If necessary, use a magnifying glass or microscope to inspect the solder joints. Since the contact area of the signal pads is tiny, even if they look like they are touching the PCB board, they might not actually be touching.

Before soldering all shield pads, check if system is working! Otherwise you might have to re-solder the socket again.

You can test the device while it is open, but the PCB board and the battery have to be in place. You will be able to see if 3G works but WiFi may not work because the antenna is on the back cover that was removed.