Adding an external antenna
You can open the Mesh Potato by removing the two screws at the back of the MP (each screw is covered with a tiny plastic disc which you can remove with the tip of a knife or tiny screwdriver). Slide the PCB out by holding the casing and pulling on the bottom of the MP.
Near the top of the PCB, you should see the UFL connector. To active the external antenna connection, remove SMD resistor R404. Add a 0 Ohm resistor or simply solder a bridge between the two pads where the location of R402 is marked.
Once you have threaded the antenna cable out through the hole you have made in the top of the MP, you should seal this hole with self-amalgamating tape to ensure a watertight connection.
See the image to the right for details as to the location of the UFL connection and resistor to remove and point to solder.