To upgrade from a 3100-iSIC to a 5100-iSIC, please follow the procedure below.
Note: This article assumes that the 3100-iSIC is already open and that the PCB and cellular modem have been removed.
1) Use step drill bit similar to the bit pictured below.
2) Drill out the existing hole that contained the RF bulkhead as pictured below.
The enlarged hole should look similiar to one pictured.
3) On the Ethernet port, wrap the wires in a zip tie to PCB.
4) Mount the Ethernet port by inserting it from outside to the inside of the iSIC box. Slide the black nut around the cable and tighten.
5) Mount the Ethernet adapter to mounting plate. Note where the yellow connector goes. Remove the existing cellular modem to make room to mount the Ethernet adapter.
6) Connect the Ethernet cable to the Ethernet adapter.
7) Return the metal plate back to its original position and install the corner screws. Be sure to the DB9 connector sticking out the side. Connect the DB9 to front.